Oddy Test Protocols

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DISCLAIMER

Oddy testing information and protocols are provided for informational purposes only. Neither AIC nor participating institutions endorse particular methods, products, businesses, or services. The following protocols are not vetted or peer-reviewed and should be assessed by each individual user for the accuracy of the results.

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Disclaimer

Oddy testing information and protocols are provided for informational purposes only. Neither AIC nor participating institutions endorse particular methods, products, businesses, or services. The following protocols are not vetted or peer-reviewed and should be assessed by each individual user for the accuracy of the results.

General Testing Information

There is a wealth of information about choosing materials and how to interpret materials testing results elsewhere on the wiki.

• Information about how to choose a material and interpret testing results is here.
• A list and description of various tests used to assess the suitability of a materials for us is here.
• General information about the Oddy Test is here.
• Guidance about planning and budgeting for an Oddy testing program can be found here.
• Resources, tips, and tricks for running an Oddy testing program are located here.
• Find a comprehensive bibliography of articles on the Oddy Test here.

MWG Round Robin Oddy Testing Protocols

The content for this section is being developed. The three Oddy Testing protocols presented here are set procedures that have been evaluated across various institutions in round robin testing by the Materials Working Group (MWG) and updated with input from different users. Individual In-House testing protocols described in the section below may resemble the tests outlined here, but with adjustments to reflect the needs of an individual institution.

Oddy Testing Protocol Based on Methods Developed by the Indianapolis Museum of Art/Winterthur Museum (IMA/W)

Dates of Use: 2019 to present

1. Introduction
2. General Overview of Test
3. Personal Protection Equipment (PPE)
4. Materials and Equipment
5. Washing Method for Glassware and Stopper
6. Metal Coupon Preparation
7. Stopper Preparation
8. Testing
9. Coupon Assessment
10. Disassembly and Reuse of Test Materials
11. Photographing/Documentation of Coupons
    

Appendix I. Materials and Supplies
Appendix II. Changes to this Protocol

Introduction

This Oddy testing protocol is based on procedures that were initially developed at the Indianapolis Museum of Art by Dr. Gregory Dale Smith and Kathleen Kiefer. In 2015, the Winterthur Museum began using the IMA protocol but integrated minor modifications that were influenced by research and testing conducted by Elena Torok, Joelle Wickens, and Samantha Owens in 2014-2015. In 2018, after discussion at the Materials Working Group annual meeting in NY, additional minor modifications were made in advance of the 2019 and 2020 MWG Round Robin Testing programs to ensure all participating groups could obtain comparable results. Since 2020, additional minor edits have been made, and are described in Appendix II.

This document is currently maintained by the Materials Working Group, Testing and Standards committee, Oddy Testing Focus Group.

General Overview of Test
The time estimate for execution of this test protocol as written is 118 minutes per test, including sample tests and control tests, photography and publishing of results in the online Test Results Table maintained on the AIC Wiki. Procedural choices, such as the use of different washing methodologies, could increase or decrease this time.

• Cleaning: 10 minutes
  
• Test Preparation: 29 minutes
  
• Test Assembly: 22 minutes
  
• Test Disassembly: 10 minutes
  
• Recordkeeping: 12 minutes
  
• Coupon Photography: 19 minutes
  
• Uploading Results: 17 minutes
  

Specifications for equipment and supplies needed to run this test are listed in Appendix 1. Unless necessary, these materials should not be substituted. In the case that a substitution must occur (a vendor no longer exists, a product is discontinued, etc.), this substitution should be documented in test results.

All tests are run in duplicate, i.e. a test consists of two stoppered test tubes containing sample material with associated coupons. Each test is assigned an identifying number that is written on an adhesive label on the outside of the tube. Replicates are labeled “A” and “B”.

Negative controls, also in duplicate, are included with every group of materials tested. A unique identifying number is also assigned to each control, and replicates are also labeled “A” and “B”.

Samples should be prepared for testing according to the Material Sample Preparation Guide presented on the AIC Wiki. If samples cannot be prepared according to these guidelines, this information should be documented in test results. All testing details and results should be recorded in a database or spreadsheet such as the Template for Recording Results provided on the AIC Wiki.

Evaluation of metal coupons and the assignment of Permanent, Temporary, and Unsuitable ratings to sample materials is guided by the Standardized Corrosion Vocabularies.

Personal Protection Equipment (PPE)
Required PPE includes nitrile gloves, safety glasses, and a laboratory coat. A particle mask or respirator is also required for metal coupon preparation if access to a fume hood or some kind of modified enclosure is not possible.
No testing materials should be touched with ungloved hands, as skin oils can cause contamination of results.

Materials and Equipment
A list with more detailed specifications can be found in Appendix 1.

• Forced air oven
• Precision Balance
• Weighing paper/dishes
• Borosilicate glass test tube, 75 mL, 200 mm (outer glassware)
• Borosilicate glass culture tube, 0.75 mL, 50 mm (inner glassware)
• Versilic peroxide-cured silicone stopper, size 27D
• Parafilm ® M
• Poly-temp PTFE tape
• Metal coupons (silver, lead, and copper), each 8 mm x 2.5 mm
• 3200 grit Micromesh
• Pointed scoring tool
• Scissors
• Tweezers
• Specimen forceps
• Glass pipette
• Templating Material (Archival Cardstock, Coroplast)
• PCC-54 Enzymatic Detergent Concentrate
• Glass beakers (1L, 150mL)
• Test tube cleaning brush
• Deionized water
• Acetone
• Kim wipes
• Nitrile gloves
• Glass plate
• Test tube holders
• Sample (approximately 2 g)
  

Washing Method for Glassware and Stoppers
Glass test tubes should be cleaned before testing using 5% PCC-54 Enzymatic Detergent Concentrate in water. Test tubes should be soaked in this solution for at least 20 minutes, rinsed thoroughly with water until suds are gone, and then triple rinsed with deionized water. Test tubes should be left to air dry, and must be completely dry before coupons, sample, etc. are inserted.
Glass culture tubes should be cleaned before testing using acetone. Submerge culture tubes in a glass jar with acetone for 5 minutes. Swish periodically. Remove culture tubes using tweezers, pour out excess acetone and place in a clean glass jar to dry.
Stoppers should be submerged/rinsed with deionized water before testing, and then wiped down using acetone on a Kimwipe.

Sample Preparation
Prepare 2.0 +/- 0.1 g of sample material.

Sample preparation will vary by sample type. Samples should be prepared according to established procedures found here.

Metal Coupon Preparation

1. Immediately after receipt, metals should be removed from original packaging and moved to Corrosion Intercept bags. If a styrene box was supplied with the lead, it may be retained and used to provide support inside the Corrosion Intercept bags.
2. Cover the working space with blotter paper for ease of capturing metallic particulates.
3. Coupons may be cut to size (0.8 mm x 2.5 mm) and then polished singly, or polished as a larger strip (e.g. 2.4 mm x 100 mm) and then cut. Cut metal foils using scissors or a scalpel (lead only) that have been cleaned with acetone. If prepared singly, coupons may be cut to size ahead of time and stored in Corrosion Intercept bags until polishing can be done.
4. Polish both sides of each metal coupon or partial sheet evenly using 3200 grit Micromesh. Polishing should be done lengthwise (i.e. along the long dimension of the strip). While holding one end of the strip against the glass plate, polish from the center of the strip towards the end, and then rotate to repeat this action to the other end. Flip the strip over and repeat again. A video of the polishing process is available here.
5. The same piece of Micromesh can be used to polish coupons of the same metal but should never be used to polish coupons of a different metal.
6. The glass plate should be cleaned with acetone between polishings of different types of metals.
7. If necessary, for large sample runs, the silver and copper coupons can be polished and sealed in Corrosion Intercept and left overnight. However, the lead coupons must be polished on the day the test is to be set up and begun.
8. Use tweezers to dip each coupon in an acetone bath. Remove the coupon from the bath and immediately wipe/dab dry using a Kim wipe. Coupons should not be allowed to air dry or left to soak in the acetone bath for prolonged periods of time or because this has been observed to cause corrosion, particularly on lead.
9. Materials (e.g. blotter) with lead particulates or used to clean equipment with lead particulate should be disposed of according to your institution’s hazardous materials policy.
   

Stopper Preparation

1. Cut three parallel 10 mm long x ~5 mm deep slits in the small end of each stopper using a scalpel blade that has been cleaned with acetone.
2. In order to streamline the stopper preparation, it may be helpful to create a template. Archival cardstock or Coroplast can be cut out to match the diameter of the stopper’s smaller end. Draw and cut out a 10x10mm square in the center. The sides of this cut square will provide a template for cutting the outermost slits. Cut the third slit in the middle between the first two (center of the square). Rinse the cut stopper surface with acetone applied by KimWipe when finished.

Test Tube Preparation and Assembly

1. Place the sample in the base of the 75 mL test tube.
2. Fill the culture tube with ~0.65 mL of deionized water using a pipette. Place the culture tube in the base of the test tube, next to the sample, using the specimen forceps. Place the prepared test tube into the test tube holder. From this point forward, care must be taken to limit rapid movement of the test tube, as water can easily spill from the culture tube.
3. Use tweezers that have been cleaned with acetone to insert each of the three coupons (Cu, Ag, Pb) into a slit in the small end of the stopper. Slits can be opened by pressing the curved sides of the stopper. Place the Pb coupon in the middle slit.
4. Insert the small end of the stopper (with coupons) into the top of the test tube. Make sure the metal coupons are not touching the sides of the glass or one another. Push the stopper in tightly.
5. Wrap approximately 10 inches of Poly-temp PTFE tape around the top of the test tube and stopper. The wrapping needs to be tight, because as the test tube heats up, the stopper will be pushed out of the tube. Wrapping the tape tightly will help keep the stopper in place.
6. Wrap Parafilm over and around the PTFE tape-covered stopper and test tube top. Again, ensure wrapping is tight and secure.
7. Label the exterior of each test tube with an adhesive white label to identify the sample inside, note A or B, and the testing start date.
8. Place test tubes in a test tube holder or large glass beaker so they can remain as upright and vertical as possible during testing.

Testing

1. Place test tubes in a forced air oven that has been pre-heated to 60oC.
2. Leave test tubes in the oven for 28 days.

• • In the first few hours of testing, check to make sure no stoppers have popped open. If a stopper has popped but is still generally resting in its appropriate position at the top of the test tube, push it back in and re-secure the area with more PTFE tape and Parafilm. If the stopper has popped out of the test tube entirely and is resting on the shelf or floor of the oven, the test tube should be re-prepared. Any type of stopper popping event should be noted in results.
  • Every few days, a quick visual inspection of test tubes should be performed to confirm that approximately the same level of water is still present in the culture tubes. If water levels are low or non-existent, there is likely a leak between the stopper and test tube. In this event, remove the test tube from the oven, remove the stopper, add more water to the culture tube, re-seal the stopper back in its appropriate position, and then place the test tube back in the oven. Any type of water loss event should be noted in results.

Coupon Assessment

1. After 28 days in the oven, remove test tubes and allow them to cool to room temperature.
2. Identify a clean, flat surface of the lab that has access to strong and consistent indoor lighting. Gather an Optivisor or magnifying loop and the standardized Corrosion Vocabularies for (Copper, Silver, and Lead) produced by The Metropolitan Museum of Art for more detail. These illustrated glossaries describe commonly-observed corrosion phenomena, and  will be used as reference to rate test results.
3. Assessment involves rating all non-control coupons as compared to the control coupons. Ratings are assigned to each metal as summarized below. In general, all coupons will receive one of three of the following ratings:
   • “Permanent” rating: The material tested may be used indefinitely in the presence of art.Coupons look similar to the controls.
     • Copper: Very slight reddening
     • Silver: Light white haze. Remnants of polishing compounds from some manufacturers can develop or appear as white splotches. This stock is generally returned to the manufacturer, however, if it makes it into a test, the white splotches are ignored.
     • Lead: Very slight darkening
   • “Temporary” rating: The material is safe for use near but not in contact with art for up to six months.
     • Copper: Slight-to-extreme reddening, rainbow-like color change, formation of up to 20 black spots.
     • Silver:  Development of a heavy white haze, yellow tarnish or orange haze, or very slight purpling.
     • Lead: Slight-to-extreme darkening, blue or rainbow tarnish, or thin yellow, orange, blue, white compacted corrosion, haze from slight crystal formation over the entire coupon, or heavier crystal formation at the interface with the stopper.
   • "Unsuitable” rating: The material should not be used in contact with or near art and another material should be found.
     • Copper: Severe blackening or formation of a heavy haze.
     • Silver: Slight-to-extreme purple, rainbow, or black tarnish.
     • Lead: thick yellow, orange, blue, or white compacted corrosion, or white fluffy crystal formation.
4. To remove coupons from a test tube, first remove the Parafilm and PTFE tape and then carefully pull the stopper out. Flip the stopper over (large side down, with coupons pointing vertically upward) onto a clean, flat surface. Squeeze the sides of the stopper to open the slits, and use clean tweezers to carefully remove Cu, Ag, and Pb coupons. Place coupons on a white piece of paper.
5. Open control test tubes and examine control coupons first. If coupons in both test tubes are minimally corroded, meaning that the corrosion phenomena observed are at or below the threshold of those rated “P” in the Standardized Corrosion Vocabularies the control test is considered valid. If corrosion phenomena observed on any metal coupon in one or both control jars are rated “T”, the control test is not valid. The corrosion phenomena present on the controls is still recorded in the test record, and individual metals for each associated sample test are described and rated according to the corrosion phenomena observed, but overall ratings for all sample tests in the batch must be retested.
6. Examine coupons from sample test tubes next. The corrosion phenomena observed on each coupon below the area that was inserted into the stopper are compared to the Standardized Corrosion Vocabularies and described separately for replicates “A” and “B” in the test record. Corrosion phenomena not present in the glossary should nevertheless be described and may be added to the glossary. The lowest of the ratings assigned to the three metals in the test is also the overall rating assigned to the material. In the event that there are moderate differences in the same corrosion phenomenon on “A” and “B” replicates, as long as the rating for both levels is still the same, the result is valid. However, if the more extreme corrosion pushes one coupon into the next rating category, or if the replicates exhibit different types of corrosion phenomena, then the sample should be retested.
7. Record test results using the supplied Template for Recording Results.
   
   

Disassembly and Reuse of Test Materialst

1. After testing is complete, disassemble tests and clean according to instructions in Section V above.
2. Samples should be discarded. Lead coupons should be disposed of according to your institution’s hazardous waste policy.
3. Glassware should be reused in future testing, so long as it does not have breaks, cracks, or other signs of deterioration.
4. If reusing stoppers in future testing, it is recommended to do so only if they were associated with tests that yielded Permanent results. Stoppers should not be reused if associated with a test that yielded Unsuitable results.
5. It is unknown to what extent reuse of stoppers from Temporary tests will introduce contaminants into the test; more research is needed in this area. Until this data is available, any reuse of stoppers from Temporary tests should be tracked and limited (for example, up to a maximum of three “temporary” tests), and each test should include one replicate that is run with a new stopper.
6. All reuse of stoppers is clearly recorded in the test record.
7. Stoppers that begin to show any evidence of material breakdown (discoloration, shedding, powdering, etc.) should also be discarded.
   
   

Photography/Documentation of Coupons

After evaluation, Oddy test coupons with matching duplicate results and passing control jars are photographed with a color reference using two different types of lighting: diffuse lighting and glancing-angle lighting. Guidelines for Coupon Photography are provided on the AIC Wiki, here.

Test results and images are uploaded to the AIC Wiki Test Results Table. Instructions are published here.

Appendix I. Materials and Supplies

ITEM	VENDOR	QUANTITY	COST
Forced Air Oven, 104 L (3.7 cubic feet)	Varies. Examples: VWR 89511-412 Thermo Scientific: Heratherm	1	$4545
Veritas Precision Balance S303	Hogentogler S303	1	$429.00
VWR Weighing Paper 10.2×10.2 cm (4×4") pack of 500	VWR 12578-165	1	$89.92
Acetone, high purity (≥99.8%), 1L	Sigma Aldrich 34850	1	$107
PCC-54 Enzymatic Detergent Concentrate, 3L bottle	Thermo Scientific 72288	1	$144.54
Micromesh 3200 grit	Conservation Resources MM-3200	Varies according to number of tests needed	$7.00 per 6” x 6” sheet
Silver foil at least 99.9% purity and 0.1mm thick, annealed, 100cm2	Fisher Scientific AA42317GH	Varies according to number of tests needed	$189
Copper foil at least 99.9% purity and 0.1mm thick, annealed, 100cm2	Fisher Scientific AA42189GH	Varies according to number of tests needed	$322
Lead foil at least 99.998% purity and 0.1mm thick, 100cm2	Fisher Scientific AA12051GH	Varies according to number of tests needed	$370
General Tools Scratch Awl tool 8.75"L x 3.75"W x 3.25"H (or any fine needle-pointed tool)	Amazon General Tools 818	1	$6.99
Fiskars All-purpose Scissors 8.25"L x 3"W	Amazon 116000-1005	1	$6.48
Scalpel handle (#3) with Surgical Grade Blades #11 20pcs	Amazon B091SQZWT3	1	$11.99
Cole-Parmer Essentials Stainless Steel Tweezers, Mini, Blunt Round Tips, Serrated Grip, 76mm	Cole Parmer UX-07398-30	1	$5.20
1ml Graduated 12/pack Glass Dropper Pipette with Rubber Cap	Walmart A2ZSCILAB	1	$9.99
Heritage Archival Bristol Board 8x10” 6pt. (Stopper cutting template)	Talas TPB570122	1	$7.00/ea
Cole Parmer Pyrex 1000-PACK Brand 1000 Low-Form Glass Beaker Starter Set; 50 to 1000 mL, 5/pk	Cole Parmer UX-34502-90	1	$53.00
Eisco™ Nylon Labware Brushes 120 x 50 mm brush head	Fisher Scientific Eisco CH0220E	1	$5.15
Kimberly-Clark Professional™ Kimtech Science™ Kimwipes™ Delicate Task Wipers, 1-Ply box of 286 wipes	Kimberly-Clark Professional™ 34120	1	$12.54
Kimberly-Clark® Safeskin Purple Nitrile Exam Gloves, Medium, Purple, Box Of 100	Kimberly Clark 55082	1	$17.00
10 in. x 12 in. x 0.09375 in. Clear Glass Plate	Home Depot 599019	1	$4.78
Cotton Blotter Paper 19” x 24”	Talas TPB139003	1 per round of tests; continual stock needed	$5.95
VWR Aluminum test tube holder 24 x 26mm (fits 24 tubes)	VWR 89259-898	1	$42.61/ea
White Laser Mailing Labels (30 labels, 1 in. x 2 5/8 in. per sheet) - 750	Avery 5260	1	$9
Stainless steel specimen forceps, 305 mm, 12” long	Varies. Example: VWR 82027-382	1	$40.28
Kimax test tubes, Type 1 Class A borosilicate glass, 75 mL, 25 x 200 mm OR VWR test tubes, Type 1 Class A borosilicate glass, 75 mL, 25 x 200 mm	VWR 89001-432 OR VWR 10545-930	1 pack of 24 OR 1 pack of 48	$85.70 OR $81.91
Saint Gobain - Versilic silicone stoppers, size 27D	US Plastics Corp. 76132	1 pack of 10	$27.12
Culture tubes, disposable, borosilicate glass, 0.75 mL, 6 x 50 mm	Varies. Examples: VWR 47729-566 OR VWR 89001-454	Case of 2,000 OR Pack of 72	$266.20 $60

'

Appendix II. Changes to this Protocol

In March 2024 this protocol was updated by the Materials Working Group to:

• Add Appendix II.
• Add the estimated time needed to complete the protocol.
• Replace several appendices with links to resources outside the protocol: Material Sample Preparation Guidelines, standardized Corrosion Libraries, Template for Recording Results, and Guidelines for Coupon Photography.
• Extend the list of Supplies and Materials to be more inclusive of items referenced in the protocol.
• Clarify steps in the washing procedure.
• Add a +/- range to the sample size specified.
• Change the coupon size to 0.8 mm x 2.5 mm
• Include an option to prepare larger pieces of metal, then cut them down to coupon size.
• Clarify steps in the polishing process.
• Add options to safely store partially-prepared coupons for short periods of time.
• Describe the use of a template in preparing stoppers.
• Adjust the coupon assessment language to more closely match the Corrosion Libraries.
• Add language describing reuse of stoppers and associated risk of contamination.
• Add language describing photography of coupons and upload of results to the AIC Wiki.
• Update Appendix I, Materials and Supplies to:
  • Generalize the metal specification, setting lower limits for purity and thickness based on the previous protocol, while updating the product numbers listed to match what is currently in use at the Metropolitan Museum. This allows users the option of choosing a purer/thinner metal that is consistent in its thickness and size, metal to metal. At the time of writing, a modest savings was also associated with this change.
  • Provide alternate vendors for specific items;
  • Include 2024 pricing.

Oddy Testing Protocol Based on Methods Developed at the Metropolitan Museum of Art (MMA)

Dates of Use: 2019 to present

1. Introduction
2. General Overview of Test
3. Personal Protection Equipment (PPE)
4. Materials and Equipment
5. Washing Methods
6. Metal Coupon Preparation
7. Jar Preparation and Assembly
8. Coupon Assessment
9. Disassembly and Reuse of Test Materials
10. Photographing/Documentation of Coupons

Appendix I. Materials and Supplies
Appendix II. Changes to this Protocol

Introduction
This Oddy testing protocol is closely based on procedures developed at the Metropolitan Museum of Art by Isabella Busarino, Alayna Bone, Catherine Stephens, and Eric Breitung, which in turn derive from methods published by the British Museum¹, where test tubes are fitted with silicone stoppers holding three metal coupons, and the Met’s original three in one jar version², where metals are hung from the rim of a beaker inside of a screw-top jar. In both cases, the corrosion states of the coupons after 28 days of aging at elevated temperatures and humidity in the presence of an unknown material are used to determine the appropriateness of a material for use in close proximity to cultural heritage materials.

After discussion at the Materials Working Group annual meetings in 2018 and 2019, minor modifications were made to the Met’s protocol (20190226_OT) in advance of the 2020 MWG Round Robin Testing program to ensure all participating groups could obtain comparable results. Since 2020, further edits have been made to the protocol to incorporate MMA updates that replace 3D printed nylon coupon holders with reusable water-jet cut stainless steel coupon holders; and to update vendor information. This new method retains the repeatability improvements of the Met’s previous method and reduces long-term costs and waste. However, based on some test results, the silver coupon is very slightly less sensitive to sulfides when using the stainless steel holder. The difference does not appear to be significant enough to warrant the continued use of nylon holders given the cost and reusability benefits provided by the steel holders. The nylon holders will remain available for purchase on Shapeways for those using the Oddy test to evaluate materials intended for use with silver collections, where the sensitivity of the silver coupon is paramount.

This document is currently maintained by the Materials Working Group, Testing and Standards committee, Oddy Testing Focus Group.

<sub>1. Korenberg, C., Keable, M., Phippard, J., Doyle, A. “Refinements Introduced in the Oddy Test Methodology”, Studies in Conservation, (August 2017), online article, 1-12.
2. Bamberger, J. A., Howe, E. G., Wheeler, G., A Variant Oddy Test Procedure for Evaluating Materials Used in Storage and Display Cases, Studies in Conservation 44 (1999) 86-90.</sub>

General Overview of Test
The time estimate for execution of this test protocol as written is 112-130 minutes per test, including sample tests and control tests, photography and publishing of results in the online Test Results Table maintained on the AIC Wiki. Procedural choices, such as the use of different washing methodologies, could increase or decrease this time.

• Cleaning: 8-26 minutes
  

• Test Preparation: 17 minutes
  

• Test Assembly: 24 minutes
  

• Test Interpretation: 14 minutes
  

• Recordkeeping: 12 minutes
  

• Coupon Photography: 19 minutes
  

• Uploading Results: 17 minutes
  

All tests are run in duplicate, i.e. a test consists of two jars containing sample material with associated lids, O-rings, coupon hangers, and glass vials. Each test is assigned a unique number, and replicates are labeled “A” and “B”.

Negative controls, also in duplicate, are included with every group of materials tested. In other words, if 15 materials are being tested on Monday, one set of controls is required. A new set of controls is required for the next group of Oddy tests that are prepared on Tuesday. A unique number is assigned to each control, and replicates are labeled “A” and “B”. For example, if two materials are being tested, jars in the batch might be numbered 1a, 1b, 2a, 2b, C1a, and C1b. A second batch of two materials might be 3a, 3b, 4a, 4b, C2a, and C2b.

For each material tested, it is recommended that at least one replicate should be run using a new lid and ring (or reused components from “permanent” tests) in the “A” replicate. The “B” replicates, including controls, may utilize reused lids. By following this practice, a mismatch between A and B replicates may reveal contamination associated with a reused “temporary” lid. However, doing so also reduces the cost savings afforded by reuse. All reuse of lids/rings is clearly recorded in the test record.

Alongside each batch of materials and controls, it is recommended to test permanent, temporary, and unsuitable standard materials as a baseline for evaluation of tests.  Ideally such standards should be agreed upon by the community. They may be commercial materials or chemicals prepared to a specified concentration. The Metropolitan Museum of Art has used Obomodulan 500 (OBO-Werke), Paper tape with potato starch, #067-25/0 (Klug Conservation), and 100% Wool Flannel style 527 (Test Fabrics) for this purpose. Development of more universal chemical standards warrants further research.

It is recommended to prepare material samples for testing according to the Material Sample Preparation Guide provided on the AIC Wiki.

Details regarding the materials tested, the testing procedure used, the weight of the jars before and after testing, the test result, and its interpretation are recorded in a custom-built database or spreadsheet such as the Template for Recording Results presented on the AIC Wiki. It is recommended to enter information about the materials being tested into the test record prior to assembling tests.

Evaluation of metal coupons and the assignment of Permanent, Temporary, and Unsuitable ratings to sample materials is guided by the standardized Corrosion Libraries produced by The Metropolitan Museum of Art (Copper, Silver, and Lead). These resources approximately represent the range of phenomena documented at The Metropolitan Museum of Art; results not captured by this glossary should nevertheless be noted in the test record, and may be added to future versions of the Glossary.

Personal Protection Equipment (PPE)
Nitrile gloves, safety glasses, and a laboratory coat are worn throughout this procedure. Hands are washed with soap and warm water prior to donning gloves to remove oils. Care is taken to always handle the metal coupons (copper [Cu], lead [Pb], or silver [Ag]) with tweezers while wearing clean nitrile gloves, as handling coupons with dirty or oily hands can cause coupon contamination. Out of a small range of gloves, Freeform ® SE blue powder-free nitrile gloves performed best in the Met’s Oddy test, and are preferred.

Materials and Equipment
This protocol specifies key equipment and supplies that are required and if possible, should not be substituted (Appendix 1: Materials and Supplies). Alternate vendors may be substituted as long as the product specification is met.

Washing Methods
One of two different washing methods (dishwasher, handwashing) is used to clean jars, lids, and Viton O-rings used in the test. KIMAX vials are always washed by hand. New components are always washed before using. New stainless steel holders should be hand washed before using the first time. Subsequently either the Hand Washing Method or the Dishwasher Method is acceptable.

Dishwasher Method (Lancer 815 LX Dishwasher)

KIMAX Jars

1. Mechanically remove all materials from jar.
2. Place each jar over a spindle jet.
3. The wash cycle includes the following steps:
   • Prewash: Rinse for 2 min.* with 60°C water
   • Wash (base): Rinse with 96 mL of NaOH in 12 L of water at 40°C for 2 min.*
   • Rinse A: Rinse for 2 min. with unheated water. Rinse with 96 mL of Phosphoric Acid in 12 L of unheated water for 2 min.
   • Rinse B: Rinse for 3 min. with unheated water.
   • Rinse C: Rinse for 3 min. with unheated water.
   • Purified Water Rinse A: Rinse for 3 min. with unheated 15 MΩ-deionized water.
   • Purified Water Rinse B: Rinse for 1 min.* with 60°C 15 MΩ-deionized water.
   • When water is being heated, it is recycled within the chamber until it reaches temperature making the times listed much shorter than the actual cycle time. After the washer reaches the prescribed temperature, it runs for the programmed amount of time. The full wash cycle requires approximately 1.75 hours. Detergents are not currently used.
4. Washed glassware is placed in a 60°C oven for drying and storage.

Viton™ O-rings, stainless steel coupon holders, and lids

1. Place on flat stainless steel mesh rack. Lids are placed upright with threads facing downward and are weighted with a stainless-steel mesh screen to inhibit flipping.
2. The wash cycle includes the following steps:
   • Prewash: Rinse for 2 min.* with 80°C water
   • Rinse A: Rinse for 5 min. with unheated water.
   • Rinse B: Rinse for 1 min.* with 80°C water.
   • Purified Water Rinse A: Rinse for 1 min. with unheated 15 MΩ-deionized water.
   • Purified Water Rinse B: Rinse for 1 min.* with 60°C 15 MΩ-deionized water.
   • When water is being heated, it is recycled within the chamber until it reaches temperature making the times listed much shorter than the actual cycle time. After the washer reaches the prescribed temperature, it runs for the programmed amount of time. The full wash cycle requires approximately 2.5 hours. Detergents are not currently used.
3. Washed Viton™ O-rings, stainless steel coupon holders,  and lids are dried and stored in a 60°C oven. Once dry, they are removed and stored in clean glass beakers.

Hand-washing Method

KIMAX Jars (alternative to dishwasher method)

1. Wash with Micro-90 Lab Cleaner (1% solution in tap water) using a laboratory cleaning brush.
2. Rinse 3 times with hot tap water.
3. Soak in room temperature aqueous sodium hydroxide (NaOH) bath with a pH of 12 for at least 15 hours (overnight). Use stainless steel tongs or large tweezers for delivering and retrieving items from the baths. Thick nitrile gloves, safety glasses, and a laboratory coat are required. Base bath preparation (yields 7.5 L): Add 3.0 g NaOH pellets to 7.5 L of deionized H 2 O. Check that the pH reads 12 on the pH indicator strip. The base bath is contained in a lidded polypropylene container within a secondary polypropylene drip container.

1. Rinse once with hot tap water.
2. Soak in a hydrochloric acid (HCl) bath with a pH of 2 for at least 15 hours (overnight). Use stainless steel tongs for delivering and retrieving items from the baths. Thick nitrile gloves, safety glasses, and a laboratory coat are required. Acid bath preparation (yields 7 L): Slowly add ~6 mL HCl (37% w/w; 1.2 g/mL density) to 2 L of deionized H 2 O. Add the remaining 5 L of deionized H 2 O. Check that the pH reads 2 on the pH indicator strip. The acid bath is contained in a lidded polypropylene container within a secondary polypropylene drip container.

1. Rinse three times with hot tap water then rinse three times with 18.2 mΩ-deionized water.
2. Dry in an oven, right side up, at 60°C.

Viton™ O-rings, lids, and coupon holders (alternative to dishwasher method)

1. Wash lids, Viton O-rings, and coupon holders in a Micro-90 Lab Cleaner solution (1% in tap water) by dipping in cleaning solution and rubbing with gloved hands or a clean sponge. Do NOT soak for any length of time in Micro-90 Lab Cleaner solution.
2. Rinse 3 times with hot tap water and 3 times with 18.2 MΩ-deionized water.
3. Store in oven at 60°C until use.

KIMAX vials

1. Place dirty vials in a 50 mL Pyrex beaker.
2. Soak vials with Micro 90 Lab cleaner for at least 24 hours (1% solution in tap water). Use a pipette to deliver the solution into the small vials.
3. Rinse 3 times with tap water. Use a pipette to deliver the rinse water into the small vials. Rinse water may be more quickly removed from the vials by upending the vials onto absorbent paper.
4. Soak in room temperature aqueous sodium hydroxide (NaOH) bath with a pH of 12 for at least 15 hours (overnight). Contain vials within a small beaker while in the bath. The beaker is contained in a polypropylene drip container during the soak. Thick nitrile gloves, safety glasses, and a laboratory coat are required. If not preparing a larger volume of base bath for jars, to prepare 1 L of base: Add 0.40 g NaOH pellets to 1 L of deionized H 2 O. Check that the pH reads 12 on the pH indicator strip.

1. Still contained within the beaker, rinse vials with hot tap water.
2. Place in a hydrochloric acid (HCl) bath with a pH of 2 for at least 15 hours (overnight). The beaker is contained in a polypropylene drip container during the soak. Thick nitrile gloves, safety glasses, and a laboratory coat are required. If not preparing a larger volume of acid bath for jars, to prepare 1 L of acid: Slowly add 0.8 mL HCl (37% w/w; 1.2 g/mL density) to 250 mL of deionized H 2 O. Add the remaining 750 mL of deionized H 2 O. Check that the pH reads 2 on the pH indicator strip.

1. Rinse three times with hot tap water then rinse three times with 18.2 mΩ-deionized water.
2. Dry and store in an oven, right side up, at 60°C until use.

Metal Coupon Preparation

Upon receipt from the supplier, all metals are immediately removed from the clear plastic film sleeve, placed back into the hard plastic box, and stored in at least one Corrosion Intercept® Ziploc® -style bag. Ideally both sides of the bag are composed of the Intercept material rather than using the style with a transparent window.

A dedicated tool (scalpel, pair of scissors) is used to cut each metal.

Copper and Silver Coupons

1. Without touching the metal, even with gloved hands, measure and cut Ag and Cu metal foils into coupons measuring 0.8 cm x 2.5 cm.
2. Soak copper and silver coupons in separate beakers of HPLC grade acetone.
3. After removing each coupon from the solvent, place it on a clean piece of aluminum foil. While holding one edge with a glove finger wrapped in a Kimwipe, wipe the exposed side dry with another Kimwipe. Flip the coupon over and repeat on the opposite side.
4. Soak the coupons in separate beakers of fresh HPLC grade isopropanol.
5. After removing each coupon from the solvent, place it on a clean piece of aluminum foil. While holding one edge with a glove finger wrapped in a Kimwipe, wipe the exposed side dry with another Kimwipe. Flip the coupon over and repeat on the opposite side.
6. Collect solvents and dispose of as hazardous waste.

Lead Coupons

1. Prepare only as much Pb foil as you will use in one batch. Sand lead coupons immediately before inserting into jars to minimize re-oxidation of the surface.
2. Cutting large strips of lead before sanding and then cutting them down after sanding makes the sanding process more efficient. The Pb foil is cut into one or more pieces 10 cm long by 0.8(x) cm wide, with x being the number of skinny strips you want to prepare for sanding. After sanding, the foil is cut into coupons measuring 0.8 cm x 2.5 cm.
3. The sanding process is completed in a homemade ‘filtration box’ with ULPA filtration.
4. Place a 12 inch by 12 inch flat glass plate inside the filtration box, and place the un-sanded lead strip(s) on top of the glass plate. The strip(s) should be made as flat as possible before sanding. The metal is very soft and flexible, so it folds and creases easily. Any folds or creases will make it more difficult to achieve an even texture after sanding.
5. Cut a 2 in square piece of 3200 grit Micromesh™ sand paper, and fold it in half twice so that it forms a 1 in square with grit on both sides. To sand, use a gloved finger to hold the closer end of one lead strip. While sanding, hold the Micromesh™ under one thumb so that pad of the thumb is flat when applying pressure and covers the entire width of the lead strip. Sand from the center of the strip to the end away from the user using even light pressure. Avoid using the tip of the thumb or pressing part of the thumbnail into the Micromesh™. Change the position of the Micromesh™ every 15-20 strokes to an unused portion of the Micromesh™. Every stroke should be straight and run all the way from the middle of the strip to the far end. Approximately 45 strokes will properly sand one half of a 10 cm by 0.8 cm lead strip. Once the first half is sanded, rotate the strip 180 degrees and sand the second half of the same side. Then flip the strip over and sand the other side using the same technique. If the lead strip elongates or stretches, too much pressure is being applied while sanding. The goal is to remove the native oxide, leaving a surface with uniform roughness, applying minimal pressure. Hanging large images of over-sanded and correctly sanded lead coupons in the preparation area is recommended for reference. A correctly sanded lead coupon is lighter in shade than the un-sanded lead, and has a consistent overall texture with no shiny patches of specular reflection.
6. After sanding lead strips, wipe with a Kimwipe® dipped in acetone, or rinse each side with acetone from a wash bottle, followed by wiping with a Kimwipe®.  Repeat until the Kimwipe® wipes clean.
7. Next, repeat with isopropanol.
8. Cut larger lead strips into skinny 0.8 cm x 10 cm strips. Then cut each skinny lead strip into 0.8 cm x 2.5 cm coupons.
9. After polishing and rinsing, dispose of Kimwipe®, Pb-contaminated gloves, and sandpaper as lead-contaminated hazardous waste.

Jar Preparation and Assembly

1. It is recommended to prepare material samples for testing according to the Material Sample Preparation Guide presented on the AIC Wiki.
2. Label sample and control jars with sample and control numbers, with duplicate pairs labeled “A” and “B” using permanent marker. Record the Control # in the test record of each sample material to be tested.
3. To prepare one sample jar, place a sheet of weighing paper on the scale and tare. Weigh 2.0 +/- 0.1g of test sample material on the paper and load into a 100 mL KIMAX borosilicate jar. Record each sample weight in the test record.
4. Dose a KIMAX borosilicate mini-test tube with 0.5mL 18.2 MΩ-deionized water using a recently calibrated micropipette. (Calibration can be checked using a precision balance and a thermometer; if recalibration is needed, it is usually sent out for service.) Load the mini-test tube into the jar alongside the sample.
5. To prepare one control jar, load only a KIMAX borosilicate mini-test tube containing 0.5mL 18.2 MΩ-deionized water. No other material is placed in the jar.
6. To a pre-washed stainless steel coupon holder or new 3D printed nylon coupon holder, attach the metal coupons by bending the coupon 5-7mm from one end and crimping it onto the holder. Insert the coupon holder into the mouth of each jar (including controls). Make sure coupons do not contact each other, the jar, or the test material.
7. Insert a Viton o-ring into each lid and lightly screw the lids onto the jars. Tighten lids to a torque of 4 Nm using a torque wrench fitted with the custom socket.
8. Weigh sample and control jars and record values in the test record.
9. Place in the oven at 60°C, leaving as much space between jars as possible for air circulation, standing upright.
10. Leave jars in the oven at 60°C for 60 minutes. Remove jars and re-tighten lids to a torque of 4 Nm while warm using a torque wrench fitted with the custom socket.
11. Record the date that the jars were placed in the oven in the test record.
12. Return jars to the oven and age at 60 ± 1.5 °C for 28 days.

Coupon Assessment

1. After 28 days in the oven, remove jars and allow to cool to room temperature. Record the date that the jars were removed from the oven in the test record.
2. Record weights of each jar in the test record.
3. For each jar, compare the weight before and after aging to determine whether each vessel was sealed during the experiment. A loss greater than 25% of the water mass (0.13 grams) one or both jars in a duplicate pair is considered a system failure and the experiment is repeated. The overall test rating is recorded as “Retest” (R). If one or both control jars fail, the corrosion phenomena present on the controls is still recorded in the test record, and coupons for each sample test are rated according to the corrosion phenomena observed, but overall ratings for all sample tests in the batch are recorded as “Retest” (R).
4. Open each jar and lift the coupon holder out. Remove coupons from the coupon holder using tweezers.
5. Unfold each coupon where it was crimped over the coupon holder. Press the coupons flat using two blocks of polished flat stainless steel, aluminum, or glass. Place the coupons on a fresh piece of aluminum foil or a petri dish. Be sure that the surface used the flatten the coupons is clean and dry before using it on the next coupon.
6. Dogear or inscribe the control coupons in the folded area over to avoid mixing samples during coupon evaluation.
7. Coupons are ideally examined by three separate individuals independently recording results and ratings in isolation. If this is not feasible, individuals may examine the coupons collectively, but should record results and ratings without consulting one another. Results and ratings are then shared within the group. If all members agree, they are recorded in the test record. If all members do not agree, the coupons are reviewed collectively, using a microscope if needed, until arriving at a consensus.
8. In general, the ratings below are used to assess non-control coupons. Please see refer to the Corrosion Libraries for (Copper, Silver, and Lead) produced by The Metropolitan Museum of Art for more detail. These illustrated glossaries describe commonly-observed corrosion phenomena, and  will be used as reference to rate test results.
   • “Permanent” rating: The material tested may be used indefinitely in the presence of art.Coupons look similar to the controls.
     • Copper: Very slight reddening
     • Silver: Light white haze. Remnants of polishing compounds from some manufacturers can develop or appear as white splotches. This stock is generally returned to the manufacturer, however, if it makes it into a test, the white splotches are ignored.
     • Lead: Very slight darkening
   • “Temporary” rating: The material is safe for use near but not in contact with art for up to six months.
     • Copper: Slight-to-extreme reddening, rainbow-like color change, or a light haze.
     • Silver:  Development of a heavy white haze, yellow tarnish or orange haze, or very slight purpling.
     • Lead: Slight-to-extreme darkening, blue or rainbow tarnish, or thin yellow/olive, orange, blue, or white compacted corrosion, haze from slight crystal formation over the entire coupon.
   • "Unsuitable” rating: The material should not be used in contact with or near art and another material should be found.
     • Copper: Severe blackening or heavy haze.
     • Silver: Slight-to-extreme purple, rainbow, or black tarnish.
     • Lead: thick yellow, orange, blue, or white compacted corrosion, or white fluffy crystal formation of any size.
9. For each test, results are assessed and recorded separately for each type of metal and for “A” and “B” replicates.
10. To assess each coupon, lift it using tweezers only. Examine the surface of the coupon at different angles under a consistent indoor light source (ex. Brightech LightView Pro LED Magnifying Glass). If the light source is adjustable, a standard color temperature and/or light level is selected that will be used for all coupons. Examination under the standard lighting may be supplemented by other lighting conditions.
11. Examine coupons from the control jars. If coupons in both jars are minimally corroded, meaning that the corrosion phenomena observed are at or below the threshold of those rated “P” in the Corrosion Libraries, the control test is considered valid. If corrosion phenomena observed on any metal coupon in one or both control jars are rated “T”, the control test is not valid. The corrosion phenomena present on the controls is still recorded in the test record, and individual metals for each associated sample test are described and rated according to the corrosion phenomena observed, but overall ratings for all sample tests in the batch are recorded as “Retest” (R).
12. Examine coupons from the sample jars. The corrosion phenomena observed on each coupon below the fold are compared to the Corrosion Libraries and described separately for replicates “A” and “B” in the test record. Corrosion phenomena not present in the glossary should nevertheless be described and may be added to the glossary at a later date. Ratings are assigned to each coupon as instructed in the Glossary. The lowest of the ratings assigned to the three metals in the test is also the overall rating assigned to the material.
13. In the event that there are moderate differences in the same corrosion phenomenon on “A” and “B” replicates, as long as the rating for both levels is still the same, the result is valid. However, if the more extreme corrosion pushes one coupon into the next rating category, or if the replicates exhibit different types of corrosion phenomena, then the rating for the metal and the material overall is “Retest” (R).

Disassembly and Reuse of Test Materials

Reuse

• Used components are not always reused. Sort lids and O-rings, separating those from jars that tested “permanent”, “temporary”, and “unsuitable”.
• Used components from “unsuitable” tests are not reused.
• Lids and O-rings from “permanent” tests may be reused indefinitely.
• O-rings from temporary tests are not reused.
• Lids from “temporary” tests may be reused. They are marked for each “T” test by scoring or using permanent marker. Additional research is needed to understand whether reuse after 4 marks is associated with irregularities in test outcomes.
• Nylon coupon holders are never reused. Steel holders can be reused regardless of prior test results.
• These practices were established to avoid the possibility of contamination from one test to another.

Disassembly

• Using a spatula, remove the O-rings from the lids.
• If not immediately photographing coupons, package them in a small polyethylene bag for storage.

Photography/Documentation of Coupons

1. After evaluation,  Oddy test coupons with matching duplicate results and passing control jars are photographed with a color reference using two different types of lighting: diffuse lighting and glancing-angle lighting. Guidance for Coupon Photography are provided on the AIC Wiki, here.
2. Test results and images are uploaded to the AIC Wiki Test Results Table. Instructions are published here.

Appendix I. Materials and Supplies

Test Assembly

• Kimble™ KIMAX™ GL 45 Media/Storage Bottles, 100mL (Product # 02-542A)
• Viton™ O-ring; size 323, 75 durometer, black (Product #V75323)
• Kimble™ KIMAX™ Reusable Borosilicate Glass Tubes with Plain End, 0.7mL (Product #14-925B)
• Shapeways Oddy Test Hanger – Triangular, laser sintered nylon coupon holder in white natural versatile plastic
• Water-jet stainless steel coupon holders – ‘Met Oddy part’ in 0.5mm 316 stainless steel; Order from Peter Hotkowski of Asterisk Incorporated, 50-3 River Street, Old Saybrook, CT 0647, 860-388-3811, peteh@asteriskinc.com
• Extra caps: Kimble™ Blue Polypropylene Cap (Product #02-542-1)

Metal Coupons

• Pb: Alfa Aesar™ Lead foil, 99.998% (metals basis), 0.1mm thick, Puratronic™ (Product #AA12051GH)
• Ag: Silver foil, 99.998% (metals basis), annealed, 0.1 mm x 100 mm x 100 mm; Fine Metals Corporation
• Cu: Copper foil, 99.999% (metals basis), annealed, 0.1 mm x 100 mm x 100 mm; Fine Metals Corporation

Metal Preparation

• Micro-Mesh, Regular 3200, sheet or roll
• Acetone, HPLC grade (Product # A949-1)
• Isopropanol, HPLC grade (Product # BP26324)
• Kimberly-Clark Kimwipes disposable delicate task wipers, 1-ply, 4½ x 8½ inches (Product #06-666A)
• Beakers (50ml, 100ml, 250ml, 600ml, 1L)
• Menda pump bottles, glass, 4oz.
• Small watch glasses, 90mm or petri dishes

Sample Preparation

• Mylar A (25 micron)
• Weighing paper
• Precision balance – Veritas S303
• End Cutting Nippers, 6-1/4" Overall Length
• Razor scraper

Tools

• Accupet 100-1000 ul Micropipette (Product #AP-1000)
• Tweezers (flat tip)
• Tweezers (blunt tip)
• Metal ruler
• Spatula & Packer Double Ended - SurgicalExcel 81-12191
• 12” Stainless Steel Forceps
• Wooden handled straight point teasing needle, (Product #19010)
• CDI 1502MRMH-QR torque wrench (2.8-16.4 Nm range)
• Shapeways Oddy Torque_8 Socket
• Small HEPA Vacuum cleaner
• Tempered glass fermentation weights

Washing Supplies - Hand

• Sodium hydroxide (NaOH) pellets, certified ACS (Product # S318-100)
• Hydrochloric acid (HCl), HPLC grade (Product # A949-1)
• Micro-90 Concentrated Lab Cleaner Detergent (Product #VV-18100-05)
• EMD Millipore 109535 MColorpHast™ pH-indicator strips (non-bleeding), pH 0-14
• 12L Gasketed storage containers
• Rubbermaid 11.4 QT Dish Pan (2-Pack)
• Bell-Art SP Scienceware dispensing jug (for de-ionized water)
• Spilltray and Drying Rack

Washing Supplies - Machine

• Lancer 815 LX Dishwasher
• LancerClean Sodium Hydroxide (NaOH) Detergent – LCD-S
• LancerAcid Phosphoric Acid Rinse – LCA-P
• Custom Stainless Steel Mesh Screen used to hold down lids: Round Hole Stainless Perforated Sheet 304 (Part#: 13523); Dimensions: 17.1” x 18.1”

Other Equipment

• Brightech LightView PRO - LED Magnifying Glass Desk Lamp
• Brightech LightView PRO - LED Magnifying Glass Floor Lamp

Other Consumables

• Freeform ® SE blue powder-free examination gloves (Microflex Product FFS-700-S)
• Corrosion intercept bags
• Hazardous waste disposal labels

Appendix II. Changes to this Protocol

In March 2024 this protocol was updated by the Materials Working Group to:

• Add Appendix II.
• Add the estimated time needed to complete the protocol.
• Replace several appendices with links to resources outside the protocol: Material Sample Preparation Guidelines, standardized Corrosion Libraries, Template for Recording Results, and Guidelines for Coupon Photography.
• Add further background to the Introduction.
• Change language describing use of new lid components in the A replicate from a requirement to a recommendation, and add the option to reuse “permanent” lids in the A replicate.
• Add a requirement to remove metal from plastic film sleeve upon receipt from the manufacturer.
• Add links to video tutorials developed by the Metropolitan Museum of Art.
• Update language about coupon holders to include stainless steel option, and describe conditions in which one might opt instead for 3-D printed nylon.
• Add a +/- range to the sample size specified.
• Adjust the coupon assessment language to more closely match the Corrosion Libraries.
• Add language describing photography of coupons and upload of results to the AIC Wiki.
• Update Appendix I. Materials and Supplies to:

• Provide alternate vendors for specific items;
• Include 2024 pricing.

Individual (In-House) Testing Protocols Referred to on the Materials Testing Result Pages

Please note that each protocol is written by the individual tester and is not necessarily in a uniform format for cross-referencing purposes. Each contributor's protocol may have changed over time based on the equipment and materials available. The dates of use for each protocol should be listed. When researching materials on the results table, please note the date tested to match to the correct protocol.

To Contribute a New Protocol

Please follow the guidelines provided on the Oddy Test Protocols Discussion Page. Use this link or the Discussion link at the top of the page. We are now providing a recommended list of sections for our protocol for ease of use in comparison between the protocols.

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American Museum of Natural History (AMNH) Oddy Test Protocol

Oddy test procedure:

All tests follow the Metropolitan Museum of Art 20190226_OT protocol outlined on this page. Tests are carried out in duplicate.

Auckland War Memorial Museum (AWMM) Protocol

Oddy test procedure:

Cleaning of glassware:

• Glassware is cleaned with water and detergent.
• Cleaned again with solvents if necessary
• Rinsed with DDI (distilled, de-ionised water)
• Flame cleaned by heating in a flame to drive of adsorbed water and other volatiles.

Coupons:

• 99% pure or better preferred Pb, Cu and Ag.
• Approximately .125 mm thickness preferred (0.005 inch)
• Cut to 1cm x 3cm.
• Remove surface oxidation/dirt with glass bristle brushes immediately before test.

Auckland Oddy Test Set Up

• Rinse in acetone.
• Insert in silicon stopper.

Set up:

• High purity silicon stoppers, cut with 3 slices across the bottom
• 1 of each coupon (Pb, Cu, Ag) placed in each slice.
• 5ml glass sample tube filled with distilled water and stoppered with cotton wool place in the bottom of each test tube.
• 1.0g-2.0g of sample place in the test tube and stopper inserted.
• Duplicate runs of samples done if possible (usually only run one duplicate of the control).
• Test tubes placed in an autoclave/oven at 50°C-60°C.
• Visually inspected and notes taken at least once a week, for 4 -6 weeks (usually just 4 weeks).
• Significant changes to the coupon surface compared to the controls recorded as a fail. Lead coupons usually become white/fuzzy/yellowish if they fail. Copper coupons may become black, brown, green, blue or other colours if they fail. Silver coupons usually darken/blacken if they fail. Pb Controls may become darker/paler, more matte, or slightly iridescent purple. Cu controls usually darken to a more orange/iridescent red colour, and may have darker spots from slight surface contaminants. Ag controls usually show no change, or slight spots of matte surface if contaminants are present.

Autry Museum Protocols by Ozge Gencay Ustun

We have adopted and adapted Brooklyn Museum's Oddy Test procedures according to our needs and experience with the test.

I. Materials you will need:

• 45 ml glass Kimax weighing bottles with gorund glass outside caps
• 20 ml beakers
• Metal coupons, silver, copper, and lead (do not reuse lead or copper coupons, this may result in inconsistent results)
• Deionized water
• Cotton swabs
• Acetone in a jar (use a separate jar for lead coupon cleaning)
• High vacuum silicone grease (Dow Corning)
• 2 glass bristle brushes (one for silver one for copper, don't polish lead to reduce health hazard)
• Gloves
• pH-indicator strips
• pliers or scissors for cutting coupons
• Disposable plastic 1ml transfer pipette
• Lab glassware cleaning detergent
• Glass wool (optional) (see procedure 9 below)

II. Test Preparation:
1. As you work, fill out the Oddy testing form. Be sure to include as much information as possible. If necessary attach a sample of the material to the form.
2. Use clean glassware. The glassware should have already been thoroughly cleaned with any lab glassware cleaning detergent and rinsed with deionized water. Rinse glassware several times with deionized water again just before use.
3. Put on gloves. For the rest of the test, nothing can be contaminated with bare hands. You must wear gloves at all times.
4. Using cotton swabs, wipe the glass containers, glass beakers and small vials with acetone. Set these pieces aside to air dry completely. Any residual solvent could contaminate the test.
5. Label your jars with the number corresponding the test material on the form.
6. Next, clean the metal coupons with a glass bristle brush. Work on a clean surface such as a piece of Mylar. Change the Mylar with each new coupon so they are not contaminated. There is a separate brush for each of the metals. Again, do not touch the coupons with bare hands. After cleaning with brush, dunk the coupons in their appropriate jars containing acetone to wash them. Take them out after a couple of minutes and let them air dry. Set aside. Handle lead with gloves and don’t polish them.
7. Weigh the material (it should be around 1.000 gr and/or fit in the 20 ml beaker) and place it in the beaker first.
8. Then insert the coupons (unbent) between the material and the beaker. Half of the coupons should touch the test material and half of it should not touch the material. This way one can test the direct impact of materials with contact and indirect impact of off-gassing when there is no contact of the material with the coupon. There will always be a setup that will be used as a control with no sample. In order to insert the coupons in the control beaker use glass wool wad (inert material) or the coupons can be bent and hang on the lip of the beaker. Do not let the coupons touch each other.
9. Pipette 1 ml of deionized water into the kimax jar.
10. Carefully place the beaker (with sample and coupons) into the Kimax glass weighing bottle. Use tweezers to lower it in.
11. Run a light amount of grease along inside the lid of the Kimax ground glass fitting with the Dow Corning high vacuum grease. Place the lid on the container lightly, rotate the lid to distribute the grease evenly and then press down tight to form a good seal. Be careful not to disrupt your coupons or the water filled glass vial. The coupons should not touch each other. Do not press hard on the lid or wiggle the lid to close it tight in the jar. This may later cause freezing of the ground glass joint after the test.
12. Place jars in lab oven. The temperature should be 60˚ C (~140˚ F).
13. Check the jars periodically (once a week) to make sure the water has not evaporated. Water evaporation indicates potential loss of VOC’s from the container – nullifying test. Avoid moving the containers to keep any water droplets on the lid from dropping onto the coupons.
14. After 28 days, remove the jars and immediately open the lids as you remove them from the oven (otherwise the lids may freeze shut forever). Record the results on the Oddy testing sheet. Ask another conservator to look at the coupons in your absence and w/o knowing your results or the materials. Compare the degree of corrosion on the metal samples to the control. Recommend whether the material fails completely, passes for temporary exhibition (~3 months), or passes for long-term use and write this on the sheet. Mention whether materials touching the coupons corroded more, less or similar when not touching the coupons (only the fumes are exposed). This way one can also recommend to use a material but with restrictions or no restrictions of contact of the material with artifacts.
15. Write a memo with your results to the departments requesting the test.
16. When your test is finished, clean your glassware. Wipe off excess vacuum grease with a paper towel first, and soak/clean in detergent tub separate from all other lab glassware. Once clean, rinse with deionized water. Once dry, place glassware back into Oddy testing tub.

III. Containers:
We have switched from the glass jars with I-Chem blue polypropylene lids for a couple of reasons. It was not possible to consistently obtain a good seal resulting in loss of moisture and VOC’s from the test material, which nullifies the test. In addition the polypropylene lids didn't last long in the oven at 60 degrees C. The test is dependant on a consistent 100% RH environment. With oven heat, the plastic lids expanded, softened and eventually developed cracks.

IV. Water:
The amount of water is dependant on the volume of the container. The ratio is roughly 1:100 water to container volume. The volume of the Kimax weighing bottle with cap is roughly 65ml, so 0.6ml of water should be added to the vial in the container. We have had better condensation results with 1 ml water (while still providing 100% RH), so 1 ml is recommended. Excess moisture will often result in corrosion of the lead coupon, providing a false result. Large droplets of water on the lid of your container dripping on the coupons or test material indicates excess water. This is less likely to occur if your test material absorbs moisture (wood or paper materials), and morelikely to occur with non-absorbing materials.

V. Materials:
Kimax Weighing Bottles with Ground Glass Outside Caps. 45 ml, 40 x 50 mm, 45/12 #03-422F ($182/6 pack; $30 each, can be found on eBay) Kimax Griffin Beakers. 20 ml #02-539-1 ($74.45/12 pack) Dow Corning High Vacuum Grease. 5.3 ox tube #14-635-5D ($25) All from Fisher Scientific (800) 926-1166

Copper foil (Cu000690) (as of June 2009) Thickness 0.3mm 300x300mm 99.98% Half hard temper flattened (GoodFellow Limited) Lead Foil. Pb0004000 Thickness 0.5 mm, 500x500mm, Purity: 99.98% PB0004000/23 (GoodFellow Limited) Silver foil 0.005" thick 99.98% purity (Sigma Aldrich Chemical Company)

Industrial Fine Eraser (metal body fine Fyberglass eraser) #AA2120 E113/F (The Eraser Company Inc. (315) 454-3237) Replacement for glass brushes (24 pack) ([glassradierer-ersatzpinsel]]) Dow Corning High Vacuum Grease 5.3 oz tube #14-635-5D (Fisher Scientific) ph-indicator strips P4786 Sigma Aldrich

British Museum Protocols

Oddy tests are performed using the ‘3-in-1’ version of the test as described in the publication Selection of materials for the Storage or Display of Museum Objects. For dry or bulk samples such as paper, fabric, boards etc., a 2 g sample is used wherever possible. Unless otherwise specified, paints are spread onto a piece of Melinex (polyester film) and allowed to air dry for four weeks, with a 12 cm x 6 cm sample size used for each test. The preparation of other sample types such as adhesives is currently under review.

pH tests are carried out for fabrics and papers. A pH test is carried out to help predict whether the material tested can safely be placed in direct contact with an organic object. The pH should be between 5.5 and 9 if the tested material is to be in direct contact with organic materials. When the pH test is performed, it is also possible to assess whether the tested material is colourfast. If the material is not colourfast, it is advised that it is not used.

Interpreting results in the Database of Materials Test Results
Oddy test results: Test results are recorded for each individual metal used in the test. However, an overall rating is assigned to indicate a material’s general suitability.

pH test results: A material with a fugitive (non-colourfast) dye or a pH value outside 5.5-9 will be classified as an unsuitable material.

The overall rating for the material is shown results table and is determined by the worst test result obtained. Pass- Suitable for permanent use; Temporary- Suitable for temporary use (less than six months); Fail- Unsuitable, do not use.

The data published in the Database of Materials Test Results (‘the database’) is regularly updated and revised. It contains the results of research work carried out by the British Museum within five years of the most recent update.

The British Museum does not use or rely on any version of the database, or any data contained within it, which is more than five years old. In making any predicative assessment of the suitability of materials based on the Oddy test or the pH test, the most up to date version of the database published on the British Museum website is the only current and authoritative statement of British Museum opinion at any given time.

Brooklyn Museum Protocol (BKM)

Overview:

The Oddy test as performed at the Brooklyn Museum follows the “3-in-1” procedure. The three metal coupons are exposed to the sample material and water vapor, in the same jar, for 28 days at 60˚ C.

When possible multiple samples of the same material are run for comparison in case of issues with the test. Three samples per material plus a control are recommended.

Materials:

• Thermo Scientific 125ml glass jars with white polypropylene lids (The type of jar used has varied over time. See Development below for details.)
• 10ml beakers
• 1ml glass vials (without plastic caps)
• Cotton to stopper glass vials
• Single-use metal coupons of silver, copper, lead.
• Deionized water
• Acetone
• Cotton swabs
• High vacuum silicone grease (Dow Corning)
• Teflon tape
• Glass bristle brushes (one for each type of metal coupon)
• Disposable Gloves
• Pliers
• Disposable plastic 1ml pipette
• Alconox cleaner

Preparation:'

Hands are washed and gloves are put on. Gloves are worn throughout test, coupons are never handled with bare hands. Gloves are changed periodically throughout test to prevent cross contamination.

Testing forms are created for each material, with a sample of the test material attached. As much information as possible about the sample material, including manufacturer, supplier, and potential museum use should be noted and results are also recorded on this form.

Glassware is thoroughly cleaned with Alconox brand glass cleaner and rinsed with deionized water. A sponge is dedicated for washing Oddy testing glassware. Clean gloves are worn when washing. Glassware is rinsed with deionized water several times just before use.

Cotton swabs are used to wipe the glass containers, glass beakers and small vials with acetone. All containers are air-dried completely as any residual solvent could contaminate the test.

Jars are labeled on the exterior with the name of the test material, date and initials of tester. A label maker is used; paper labels can degrade over time in the oven.

The outside of each lid is labelled with the number of times it has been used. A label maker is used.

The metal coupons are cleaned with a glass bristle brush. Work is done on a clean surface, such as a piece of Mylar or paper. The Mylar/paper is changed with each type of coupon so they are not contaminated. There is a separate brush for each type of metal. After cleaning with brush, the coupon surfaces are wiped with acetone on cotton swabs and set aside. Extra care is taken with lead coupons to contain lead dust and to dispose of any residue appropriately.

Each test material is prepared by cutting to a small size that will fit within the 10ml beaker. An appropriate method of cutting is determined by the test material, but often a fresh scalpel blade or other clean tool is used. If the material needs to be prepared or cured, this is carried out in advance and the cure time is noted on the test form.

Each test material is placed in a separate 10ml beaker. Coupons are bent into U-shapes and hung on the edge of each 10ml beaker; they should not touch each other. Pliers are wiped with acetone before bending each type of coupon; a clean paper or Mylar interleaving may also be used in-between the coupon and plier teeth.

1 ml of deionized water is pipetted into small glass vials, not into the beakers themselves. With tweezers, a small ball of cotton is stuffed into the top of the vial without letting it fall into the water.

The control beaker is prepared with all the same materials (coupons, water, cotton) except the sample.

Using tweezers, the beaker (with sample and coupons hanging on beaker lip) is placed into a larger glass jar. A vial of water with cotton ball is also added.

A light amount of Dow Corning high vacuum grease is run along the outside lip of glass jar. The cap is twisted on tightly.

Jars are placed in the lab oven. The temperature is set to approximately 60˚ C (~140˚ F). After 30 minutes, the screw caps are twisted another ¼ or ½ turn to ensure an air-tight seal. The lids are wrapped with Teflon tape after tightening.

The jars are checked once a week to make sure the water has not evaporated. Water evaporation indicates potential loss of VOC’s from the container nullifying test. Care is taken to avoid moving the containers in order to keep water droplets on the lid from dropping onto the coupons.

After 28 days, the tests are removed and results recorded on the testing form and in the Brooklyn Museum’s Oddy testing database. The sample coupons are compared with the coupons of the control. Possible results are: fails completely, passes for temporary exhibition (~3 months), or passes for long-term use.

After the test is finished, lids from tests that passed or temporarily passed are kept. Lids from tests that failed and that have warped/cracked are discarded. Glassware and lids are cleaned immediately. Excess vacuum grease is thoroughly wiped off with a paper towel. Lids and vessels are washed and clean in an Alconox tub separate from all other lab glassware. Labels recording number of uses are left on lids.Once clean, vessels are rinsed with deionized water.

Development:

Over time the procedure has changed slightly as new suppliers were found for materials. The museum has experimented twice with using ground glass lids for the jars. Each time the difficulty opening glass lids ultimately required a return to polypropylene lids.

Metal Coupons (February 2020): A new supplier of silver for the coupons was found.

Containers (February 2019): The procedure switched back to the glass jars with polypropylene lids, because the glass vials with glass lids could no longer be opened after the tests were conducted. The polypropylene lids still introduce a possible issue of contamination and are not indefinitely reusable as they eventually warp and crack. Currently only lids from controls and tests that passed or temporarily passed are reused. The number of reuses is recorded. When tests fail, lids are disposed to reduce contamination issues.

Containers (June 2016): Switched to Kimex glass jars with glass lids. The blue polypropylene lids introduce a possible issue of contamination and are not reusable for repeated testing. Monitoring of issues with the lids is ongoing.

Containers (January 2011): Switched back to the glass jars with I-Chem blue polypropylene lids because after several uses of the glass vials, an adequate seal was not achieved and the lids could no longer be opened after the test was conducted. Grease applied around the caps of the I-Chem bottles along with Teflon or Mylar was tested and seemed to reduce/prevent any loss of vapor from the bottles. A consistent 100% RH environment was maintained even if vapor was lost from the bottle as long as some liquid remained in the vial. Lids may need to be replaced as the plastic expands, softens and eventually develops cracks.

Containers (February 2006): Switched from the glass jars with I-Chem blue polypropylene lids. It was not possible to consistently obtain a good seal resulting in loss of moisture and VOC’s from the test material, which nullifies the test. The test is dependent on a consistent 100% RH environment. With oven heat, the plastic lids expanded, softened and eventually developed cracks.

Water (January 2011): Water is no longer placed at the bottom of the larger jar and have switched to small glass vials with cotton at the top of the vial. The amount of water is dependent on the volume of the container. The ratio is roughly 1:100 water to container volume. The volume of the jar with cap is roughly 125ml, so 1.25ml of water should be added to the vial in the container. Better condensation results have been obtained with 1 ml water (while still providing 100% RH), so 1 ml is recommended. Excess moisture will often result in corrosion of the lead coupon, providing a false result. Large droplets of water on the lid of your container dripping on the coupons or test material indicates excess water. This is less likely to occur if your test material absorbs moisture (wood or paper materials), and more likely to occur with non-absorbing materials.

Materials:

• Thermo Scientific™ Wide-Mouth Short-Profile Clear Glass Jars with Closure. 125ml, 69x60mm, #120-0125
  
• Thermo Scientific™ PTFE-Lined Closed Caps. 58-400ml, #B167-5800BL
  
• Kimax Griffin Beakers. 10ml #02-539C
  
• Fisherbrand Autosampler Shell Vials for Waters Autosamplers. 1ml #03-391-23
  
• Dow Corning High Vacuum Grease. 5.3 oz tube #14-635-5D Fisher Scientific (800) 926-1166
  
• Copper Foil. (99.98% purity, 0.25 mm thick, 49.5 g) #349178-49.5G
  
• Silver Foil. Ag : Silver foil, 99.998% (metals basis), annealed, 0.1 mm x 100 mm x 100 mm; Fine Metals Corporation http://www.finemetalscorp.com
  
• Lead Foil. (99.9% purity, 0.5 mm thick, 56g) #265918-56G Aldrich Chemical Company (800) 325-3010
  
• Industrial Fine Eraser. (metal body fine Fybrglass eraser) #AA2120

E113/F Fine Fybrglass refills. (refill tips for metal body) #AA0019 The Eraser Company Inc. (315) 454-3237 http://www.eraser.com/browsecat.cgi?mode=open&id=113

Cincinnati Art Museum (CAM) Protocol

There is no protocol information at this time.

The Cleveland Museum of Art (CMA) Protocol

Disclaimer Prior to 2018, the CMA used the protocol attached here.Media:CMAOddyPre2018.pdf
Please read through each protocol before determining suitability of use for any materials tested prior to 2018.

Test Method Description:
This method is derived from the protocol released by the Metropolitan Museum in 2018. Minor changes have been made to reflect the way the procedure is enacted at the CMA. The CMA's previous version of the Oddy test, used from 2009-2017, incorporated methods adapted from the Philadelphia Museum of Art. The current CMA protocol was edited and enacted by Laura Gaylord Resch in November of 2018.

I. Personal Protective Equipment (PPE):
Nitrile gloves, safety glasses, and a laboratory coat are worn throughout the Oddy testing procedure. Hands are washed with soap and warm water prior to donning gloves to remove oils. Care is taken to always handle the metal coupons (copper [Cu], lead [Pb], or silver [Ag]) with tweezers while wearing clean nitrile gloves, as handling coupons with dirty or oily hands can cause coupon contamination.

II. Washing Method:
Glassware Preparation:

1. Wash with Micro-90 Lab Cleaner (1% solution in tap water) using a laboratory cleaning brush and tap water.
2. Rinse 3 times with hot tap water.
3. Soak in room temperature aqueous sodium hydroxide (NaOH) bath with a pH of 12 for at least 15 hours (overnight). Use pipets to deliver the solutions into the small vials. Use 10” 4 stainless steel tongs for delivering and retrieving items from the baths. Thick nitrile gloves, safety glasses, and a laboratory coat are required.
a. Base bath preparation (yields 7 L): Add 3.0 g NaOH (s) to 7.5 L of deionized H2O. Check that the pH reads 12 on the pH indicator strip. The base bath is contained in a lidded polypropylene 12-quart container within a secondary polypropylene drip container.
4. Rinse with hot tap water then place in a hydrochloric acid (HCl) bath with a pH of 2 for at least 15 hours (overnight). Thick nitrile gloves, safety glasses, and a laboratory coat are required.
a. Acid bath preparation (yields 7 L): Slowly add ~6 mL HCl (37% w/w; 1.2 g/mL density) to 2 L of deionized H2O. Add the remaining 5 L of deionized H2O. Check that the pH reads 2 on the pH indicator strip. The acid bath is contained in a lidded polypropylene 12-quart container within a secondary polypropylene drip container.
5. Rinse three times with hot tap water then rinse three times with 18.2 mΩ-deionized water.
6. Dry in an oven, right side up, at 60°C.
Viton™ o-rings, nylon coupon holders, and lid preparation:
1. Wash lids, coupon holders and Viton™ o-rings in a Micro-90 Lab Cleaner solution (1% in tap water) by dipping in cleaning solution and rubbing with gloved hands or a clean sponge. Do NOT soak for any length of time in Micro-90 Lab Cleaner solution.
2. Rinse 3 times with hot tap water and 3 times with 18.2 MΩ-deionized water.

KIMAX™ Vial preparation:
Same as instructions outlined in the dishwashing method section II 1.-.6 above.

III. Metal Coupon Preparation
1. Measure and cut high purity (99.998% or higher) metals (Ag, and Cu) into coupons measuring 0.8 cm x 2.5 cm. Cut Pb into 0.8 cm x 10 cm strips to prepare for sanding.
a. Clean scissors before cutting each metal. Wipe scissor blades with a Kimwipe® dipped in acetone. Wipe dry. Next, wipe with a Kimwipe® dipped in isopropanol. Wipe dry.
2. Soak copper and silver coupons in a small beaker of acetone and wipe dry with a Kimwipe®. Next, soak the coupons in fresh HPLC grade isopropanol. Remove from beaker and wipe dry with a Kimwipe®. Collect rinse solutions and disposed of as hazardous waste.
3. Place a 12” x 12” piece of Mylar™ inside the fume hood. Sand both sides of the lead coupon, sanding only along the length of the coupon, away from the user with an unused area of folded 3200 grit Micromesh™ sand paper and even, light pressure. Each side of the long strip of lead should take approximately 35 seconds to sand.
a. Sand lead coupons immediately before inserting into jars to minimize re-oxidation of the surface.
4. After sanding 0.8 cm x 10 cm lead strips, rinse each side with acetone from a wash bottle and gently wipe with a Kimwipe®. Repeat. Next dip a Kimwipe® in isopropanol and wipe each side of the lead strip. Repeat. Cut each lead strip into four 0.8 cm x 2.5 cm coupons.
5. After polishing and rinsing, dispose of Mylar™, Pb-contaminated gloves, and sandpaper as lead contaminated hazardous waste.
6. All metals are stored immediately upon receipt from the supplier in at least one Intercept® Ziploc®-style bag. Ideally both sides of the bag are composed of the Intercept material rather than using the style with a transparent window.

IV. Jar preparation and assembly
1. Run all tests in duplicate, including controls. Produce one set of controls for each group of tests.
2. To prepare one jar, place a sheet of weighing paper on the scale and tare to zero. Weigh 2g of test sample material on the paper and load into a 100 mL borosilicate jar (Kimble™ KIMAX™ GL 45 Media/Storage Bottles, Product # 02-542A, 100mL) along with a borosilicate mini-test tube (Kimble™ KIMAX™ Reusable Borosilicate Glass Tubes with Plain End, Product #14-925B, 0.7mL) containing 0.5mL 18.2 MΩ-deionized water. Dose 18.2 MΩ water into the mini-test tube using a recently calibrated micropipette.

a. Each control jar contains 0.5 mL of water in the KIMAX™ test tube as well as the metal coupons folded over a coupon holder. No other material is placed in the jar.

3. To a pre-washed new 3D printed nylon coupon holder, attach the metal coupons by bending the coupon 5-7mm from one end and crimping it onto the holder (see Figure 4). Insert the coupon holder into the mouth of the jar.

a. Make sure coupons do not contact each other, the jar, or test material.

V. Assessment at completion of testing

1. After 28 days in the oven, remove jars and allow to cool to room temperature.

2. Record weights of each jar. Compare to the pre-aged weights to determine whether each vessel was sealed during the experiment. A loss greater than 25% of the water mass (25% of 0.5 grams, or a loss of more than 0.13 grams) is considered a system failure, and the experiment is repeated.

3. Open jars and lift the coupon holders out of the jars. Remove coupons from the coupon holders using tweezers.

4. Unfold the coupon where it was crimped over the coupon holder. Scribe the inside of each coupon across the width of the coupon where it met with the holder using a dissection needle. Press the coupons flat using two blocks of polished flat stainless steel, aluminum, or glass. Place the coupons on a fresh piece of aluminum foil or petri dish.

5. Inscribe the letter “C” in the portion of the control coupons that were folded over to avoid mixing samples during coupon evaluation. Assess the controls for corrosion. If they are minimally corroded, proceed. If the coupon corrosion of a given metal in one jar is significantly different from that in the other or if there is significant corrosion, repeat the experiment.

6. Using a spatula, remove the o-ring from the lid.

7. The following ratings are used to asses non-control coupons:

a. “Permanent” rating: The material tested may be used indefinitely in the presence of art.

i. Coupons look similar to the controls.

ii. For silver, remnants of polishing compounds from some manufacturers can develop or appear as white splotches. This stock is generally returned to the manufacturer, however, if it makes it into a test, the white splotches are ignored.

b. “Temporary” rating: The material is safe for use near but not in contact with art for up to six months.

i. Copper: Slight reddening, yellowing, or rainbow-like color change, formation of up to 20 black spots

ii. Silver: Slight yellowing, purpling, or darkening.

iii. Lead: Darkening, yellow/olive tarnish, haze from slight crystal formation over the entire coupon, or heavier crystal formation at the interface with the coupon holder.

c. “Unsuitable” rating: The material should not be used in contact with or near art and another material should be found.

i. Copper: Severe blackening or severe reddening or matte-textured surface.

ii. Silver: Severe color change to dark purple, yellow, or black.

iii. Lead: White fluffy crystal formation.

Cultural Restoration & Preservation (CRP) Oddy Test Protocol

Procedure

1. Samples are prepared while wearing nitrile gloves to prevent cross contamination or imparting of any materials that may affect testing. Small swatches of each of the materials to be tested are cut roughly 2” in length from the original samples. Samples are then placed in glass laboratory jars with screw-on lids. These jars are then labeled on the exterior with the appropriate sample name, number, and date.
2. Tweezers are used to place one of each of the polished, degreased metal coupons of lead foil (0.1mm Puratronic 99.998% produced by Alfa Aesar), silver foil (0.1mm Puratronic 99.998% produced by Alfa Aesar), and copper foil (0.127mm Annealed 99.9% produced by Alfa Aesar) in each jar. The coupons are never touched with bare hands. The metal coupon bags are kept sealed. Lead corrosion appears when the presence of organic acids within the atmosphere forms. These corrosion by-products are represented as a powdery white to a reddish brown material on the surface of the lead coupon. The sterling silver coupon is sensitive and reacts to sulphur within the atmosphere. This turns the coupon black and, in extreme instances, causes pitting and etching of the silver coupon surface. The copper coupon reacts to chlorides, oxides and sulfur compounds within the test environment, forming a variety of corrosion compounds ranging from dark brown to powdery green or whitish precipitate on the coupon.
3. After the jars receive metal coupons and a testing sample, a sterile cotton ball is placed within the same glass testing jar. This cotton ball receives three drops of de-ionized water by pipette to create the elevated humidity for testing. It should be noted that the metal coupons, as well as the cotton ball, are situated within the jar so as to not come in direct contact with the test material itself.
4. Each jar receives a sheet of aluminum foil over the opening of the jar to create the appropriate seal to the container. Over this aluminum foil, the metal cap is screwed down tightly, and in this way the jars are prepped for the testing process.
5. The samples within their testing jars are transferred to a QL Model 10 lab oven. The jars are placed on wire metal racks within the oven. The oven is then maintained at 40 degrees Celsius for 28 days, as per the original Andrew Oddy protocol.
6. At the same time as prepping the individual samples for the oven, a control jar for each sample is created. Tweezers are used to place one A-D (acid detection) strip into each control jar containing a sample of each of the materials with metal coupons. These jars are sealed and labeled in the same manner as the oven sample jars. The strips are never touched with bare hands. The A-D bags are kept sealed and out of the light. These jars are maintained in ambient room conditions, 68 to 70 degrees Fahrenheit for the duration of the test to determine if outgassing of contaminants occurs at room temperature. Strips react to acid vapors turning from dark blue to green to yellow. Test results often occur within 24 to 48 hours after testing begins. The control samples are photographed and evaluated to ensure that there is no change or reactivity of the control during the 28 day period. The control coupons should not show any alterations or develop corrosion differing from the original conditions of the coupons at the start of the Oddy test.
7. Samples are removed from the oven and then evaluated by the use of a microscope. Samples are placed under a Bausch and Lomb Stereo Zoom Microscope, equipped with microscope mounted full spectrum light source. The coupons are compared against images of the coupons prior to conducting the test to determine any reactivity. The metal coupons are also compared visually to the metal coupons of the control jars.

Evaluation
All three coupons per sample were analyzed as follows: Coupons are removed from their discrete jars. Lead, silver and copper coupons are then analyzed to determine reactivity and corrosion products. The criterion for pass or fail is a visual evaluation. In order to pass the test, a material should cause no more corrosion on any of the metal coupons than caused by the reference blind (“control”) test. Corrosion of the different metals gives a clue by the way they respond to which gasses the materials emit. Silver is corroded by reduced sulfur-compounds and carbonyl sulfides, and lead is corroded by organic acids and aldehyde and acidic gases. Copper is corroded by chloride, oxide and sulfur compounds. A-D strips start out indigo blue in color. Their color is altered when exposed to an acidic environment changing from blue to green or yellow depending upon the acidity. This establishes the pH range once compared to the acid detection standard. Other gases also cause various types of corrosion. These other corrosion gases are not directly identified within this testing protocol. A-D strips are analyzed against the control jar and A-D color chart to determine exposure to acids and aldehydes.

Field Museum of Natural History (FMNH) Protocol

General Procedure
The Field Museum uses a modified version of the British Museum 3-in-1 test. 2 gram material samples are placed in 55ml borosilicate glass tubes. Along with the samples, each tube also contains two 0.8 ml borosilicate culture tubes (each is filled with 0.5ml of DI water and plugged with a small cotton wad). High-purity silver, copper, and lead sheets are cut into 25 x 10mm coupons and polished with glass-bristled brushes. One of each type of metal coupon is inserted into a corresponding slit in the underside of a silicone stopper, which is then snugly inserted into the top of a sample tube. The assembled test tubes are placed in a test tube rack. Three control test tubes (containing coupons and water vials but no sample) are added to the rack as well. The rack is secured with Plexiglas and Velcro to keep the stoppers from coming out. The rack is placed in a lab oven at 60 degrees Celsius for 28 days. After the test period, the condition of each coupon is examined under a stereomicroscope and assigned a pass, fail, or temporary/limited use designation.

Cleaning
Glassware

1. The glassware is immersed in 10% nitric acid overnight to remove soiling. To prepare the acid solution,1 part 70% nitric acid is added to 6 parts deionized water. PPE (gloves, lab coat, and face shield) is worn when handling acid.
2. Upon removal from the acid solution, the glassware is rinsed with hot tap water and cleaned with neutral soap (i.e. Orvus liquid). It is then rinsed thoroughly with tap water followed by another rinsing using deionized water. Glassware is placed in the oven (in an upright position) at 60°C to dry.

Stoppers

1. Stoppers are immersed in deionized water overnight.
2. The stoppers are then cleaned using neutral soap (i.e. Orvus liquid) and hot water. Next, they are rinsed with tap water and then thoroughly with deionized water. The stoppers are placed in the oven at 60°C to dry. It is critical to make sure that the slits cut in the stoppers are clean and dry before they are used.

Preparing Coupons

1. Three Petri dishes are filled with acetone and covered (one Petrie dish for each metal).
2. Each metal is prepared sequentially to reduce cross-contamination. Each tool is cleaned between metals. Gloves are worn. The coupons should not be touched with bare hands.
3. The metal sheets are sectioned into rectangles measuring 10 x 25 mm using a template, ruler, and scribe.
4. Any oxide layers are removed from the metal surface by abrading with a glass bristle brush. There are three brushes, one for each metal. The polishing is done in the fume hood on Mylar, using a large enamel tray to contain the glass bristles. The nozzle of a HEPA vacuum is suspended over the edge of the tray as well.
5. After polishing, the metal is wiped with acetone on a Kimwipe to remove gross metal and fiber particulates.
6. The coupons are then cut with the metal shears and placed in the appropriate Petri dish filled with acetone.
7. Gloves are changed, the enamel tray is cleaned, and the Mylar is changed out.
8. The process is repeated for each metal type. Currently, the FM is only running triplicate samples on high-use materials but is attempting to make this the standard as time and staffing allows.

Interpreting Results

1. The coupons are photographed with a color standard in high resolution at multiple angles. The FM is exploring diffuser options to lower reflection.
2. The coupons are examined with the naked eye and then under a stereomicroscope.
3. Designations are assigned using the GCI Revised Guidelines:

P = Permanent. No visible corrosion. Red orange iridescence often appears on the copper control. Coupon should not have lost polished surface. Lead control may acquire a gray haze or purple hue.
T = Temporary. Slight tarnish or film of corrosion: discoloration, often seen along lower edge and sides or as a few localized small spots of corrosion. Suitable for temporary use (less than 2 years).
L = Limited Use. Objects, such as those comprised of lead or calcite (calcium carbonate), e.g., shell, that are hypersensitive to corrosion by volatile organic acids, should not be exhibited with these materials.
U = Unsuitable. Corrosion clearly visible. Unsuitable for display case or storage use.

Materials List

1. Borosilicate glass test tubes, 55ml: Kimax 45048-25150 KG-33
2. Silicone stoppers: Cole-Parmer High-purity silicone stoppers, size 4 (27D)
3. Borosilicate culture tubes, 0.8 ml (6x50mm tubes): Kimble Chase 73500-650
4. High-purity copper, silver, and lead foils (>99.5% purity, 0.1mm thick)

Getty Conservation Institute (GCI) Protocol by Mara Schiro

I. Experimental Overview
The principle of the Oddy test is that a sample of proposed storage or display material (the test material) is enclosed in an airtight reaction vessel with three small metal coupons: copper, silver and lead. This is a test of reactivity of gasses that evolve off of the test material, not a contact test so the metal coupons do not touch the test material or each other. The evolution of gases from the material and any corrosion reactions are accelerated by elevating the temperature to 60°C and adding a small amount of water to maintain the relative humidity at 100% for the duration of the test. For every set of samples, one control test is simultaneously carried out with water and the metal coupons but no test material to measure the effects of elevated temperature and relative humidity alone. These coupons in the control environment are called the blanks. After 28 days at elevated temperature and relative humidity, the experimenter visually assesses the degree of corrosion on the test coupons and compares them to the corrosion on the blank coupons. If no alteration has occurred to the test coupons, the material passes. If any corrosion has occurred on any of the coupons, the luminosity of one or more of the coupons has deteriorated or the color of any of the coupons has changed dramatically, the test material fails the Oddy test and the material is not recommended for use. The purpose of this test is not to identify what type of volatile compound is being released from the test material. A failure in the silver coupon could be an indication of the following types of gasses evolving off of the test material: reduced sulfur compounds and carbonyl sulfides. A failure in the copper coupon could be an indication of the following types of gasses evolving off of the test material: chlorides, oxides, and sulfur compounds. A failure in the lead coupon could be an indication of the following types of gasses evolving off of the test material: organic acids, aldehydes, and acidic gases. This list is not comprehensive and should only be used as a starting point for future research if more investigation is required.

II. Materials
Coupon size does not effect corrosion but standard sizes are used for consistency of analysis. 1. New or used silver coupons (1 per sample + 1 for control) 1.1. Purity: metal foil of no less than 99.5% purity 1.2. Size: 10 x 15 mm by about 0.1 mm thick Goodfellow Silver foil AG000450/11 2. New or used copper coupons (1 per sample + 1 for control) 2.1. Purity: metal foil of no less than 99.5% purity 2.2. Size: 10 x 15 mm by about 0.1 mm thick Alfa Aesar copper foil 99.9%, 0.254mm thick, Stock #13379 3. New lead coupons (1 per sample + 1 for control) 3.1. Purity: metal foil of no less than 99.5% purity 3.2. Size: 10 x 15 mm by about 0.1 mm thick Alfa Aesar lead foil 99.9%, 0.1mm thick, Stock #42708 4. Felt-tipped rotating polisher Freedom Electric Company, Serial # C850026 5. Metal polish: polish metal fledge metal-polish from SPI supplies, Stock #1027 6. Lint-free polishing cloth 7. Mr. Clean liquid cleaning solution 8. Toothbrush or other soft-bristled brush for cleaning 9. Acetone 10. Deionized or distilled water 11. Small well-sealed clean glass jars VWR, I-Chem brand 60 mL jars (P/N 15900-242) 12. Glass ring no more than 3cm in diameter, or beaker of same size (20mL) 13. Glass test tubes VWR, Disposable Culture Tubes (P/N 47729-566), Durex Borosilicate Glass Size 6x50 mm 14. Clean single-use gloves (2 pairs) VWR, Esteem Stretch Nitrile Gloves (P/N 8817N) 15. Safety glasses 16. Clean tweezers 17. Kimwipes or other lint free laboratory-grade tissue paper

III. Sample Selection
1. The sample should be freshly obtained from the manufacture. • Most materials are most corrosive when first produced and should be tested in this state. • Manufacturers can change formulation of their products at any time without notification so you cannot test an old material if new material will be used. 2. In the case of composite materials (i.e. epoxies) the sample should contain all components in the form that they will be used. 3. Paints, varnishes and adhesives should be tested as freshly cast films. 4. Each sample should be approx. 1x1x1 cm in size to easily fit into reaction vessel. 5. Approximately 2 grams of test materials should be used. With lighter bulkier materials is may be impossible to use that much sample and the following guidelines can be used instead: • Dense materials (i.e. epoxy) at least two 1x1x1 cm cubes • Bulky materials (i.e. foams and boards) four to six 1x1x1 cm cubes • Light materials (i.e. fabrics or paints) ten to twenty 1x1 cm squares

IV. Coupon Preparation
You will need one of each coupon per sample plus one extra of each coupon for the control. For those inexperienced with the Oddy test, consider preparing 2-5 replicates of each sample and of the control to ensure accurate results and prevent false-negatives.

1. Polish Coupons
1.1. Put on clean gloves and safety glasses. 1.2. Cut new lead coupons using clean scissors and set aside until Reaction Vessel Set-Up. • DO NOT polish or wash lead coupons. 1.3. Select new or used silver coupons to polish. 1.4. Select new or used copper coupons to polish. 1.5. Use metal polish and felt-tipped rotating polisher to remove corrosion and tarnish from the front, back and sides of each coupon so that they are untarnished and shiny. • Always wear safety glasses and gloves when polishing. • Polish all silver and copper coupons even if they are new. 1.6. Use lint-free cloth to finish polishing and remove all residue, making sure to thoroughly clean front, back and sides of each coupon. • From this point forward, only handle coupons with tweezers!

2. Clean Coupons
2.1. Put on clean gloves. 2.2. Submerge silver and copper coupons in Mr. Clean liquid cleaning solution. • Mr. Clean is used because (unlike dish soap or detergents) it doesn’t leave a residue. • DO NOT polish or wash lead coupons. 2.3. Remove one coupon at a time from cleaning solution using tweezers and scrub both sides with a toothbrush against the palm of your gloved hand. 2.4. Thoroughly rinse each copper or silver coupon with dionized or distilled water. 2.5. Submerge coupons in acetone. They can either be removed immediately or left submerged for short periods of time while remaining coupons are cleaned. 2.6. Using tweezers, remove coupons from acetone a dry with a kimwipe. 2.7. Using tweezers, carefully inspect all coupons to ensure they are free from tarnish, residue, corrosion, dust or finger prints.

V. Reaction Vessel Set-Up
You will need one reaction vessel per sample plus one extra for the control. 1. Thoroughly clean reaction vessel (I-Chem brand 60mL jar) using Mr. Clean. 2. Rinsing three times with deionized/distilled water and dry with a lint free cloth. 3. Label reaction vessel with a unique sample ID number (instructions below in VII. Using Computer Database VII.22. VII. .2Obtain a new sample ID) 4. With gloved hands, bend each coupons over the glass ring or beaker so that the coupons are suspended in an upside-down U or V shape and don’t touch one another. 5. Gently place ring into jar. 6. Arrange test material samples inside or around outside of ring ensuring that none of the sample is in contact with the coupons. 7. Fill two test tubes with water. If your material is perticuarly absorbent, you may need to fill more than 2 tubes to maintain 100% relative humidity throughout the duration of the test. • The ideal water to air volume ratio of 1:100 8. Check that none of the coupons touch the test material or each other. 9. Tightly seal jars. 10. Place in 60° oven. 11. After a half hour in the oven, re-tighten the jars and return to the oven.

VI. Analysis of Results
1. After 4 weeks (28 days) remove reaction vessels from oven.
2. Open each reaction vessel and using tweezers to remove metal coupons and lay them out onto a labeled piece of paper.
Control Blank Test Material Sample ID Test Material Sample ID Silver (Ag) Copper (Cu) Lead (Pb)
3. Discard test material in trash and discard glass test tubes in glass disposal container.
4. Classify the results for each metal coupon as follows: • P = Permanent. No visible corrosion. Suitable for permanent use. Coupons should not have lost luster on polished surfaces. All copper coupons including the control will naturally turn a darker orange when exposed to heat and humidity. Some lead coupons including the control may acquire a slight purple hue. • T = Temporary. Slight tarnish or film of corrosion, discoloration. In the guidelines for the test these are considered suitable for temporary use. However, the Getty practices a more conservative approach and almost never uses materials that have been deemed suitable for temporary use. • U = Unusable. Corrosion clearly visible. Unsuitable for display case or storage use.

The Green Challenge Protocol by Christian Hernandez

This protocol was heavily inspired by “Testing Materials for the Storage and Display of Artefacts” by Thickett and Green, and developed for the 2012 graduate thesis work of Christian Hernandez.

I. Supplies:

• Oven: A Blue M Stabil-Therm® Bench Type Gravity Convection Laboratory Oven Model OV-12A was used by the tester
• Metal Foils at >99.5% purity: Lead, Copper, Silver
• Glass Test Tubes: 3-50 mL + 3-1 mL vials per material + Control
• Silicon Stoppers for each 50mL test tube.
• Distilled Water: .5 mL / 1 mL vial. pH 7. pH strips, NaOH
• Clean Surfaces: Cover surfaces with Mylar/Paper.
• Equipment: Camera, Stereomicroscope, Scale
• Documentation: Temperature log, Materials Log
• Glass Bristle Brushes: 3. Label with what metal it is used with.
• Materials to be tested: 6 gm/material + sample
• Test Tube Tray(s)
• Piece(s) Coroplast: Tray-Sized, Velcro
• Acetone/Alconox
• Kim-Wipes/Cotton Swabs
• 2 Tweezers
• Box of Powderless Nitrile Gloves
• Small Transfer Pipette/Dropper
• N-19 respirator
• Scissors, Xacto-knife
• Teflon Tape

II. Protocol
Before beginning, select your materials and keep a sample for future reference. Record the material's name, retail product ID#, Manufacturer and/or retailer, date purchased and notes (finishes, colors etc.). Assign each material an ID#, with the first number for the control and the second for the material. A table like the one below may be helpful in keeping track of this information.

ID#	Name	Product ID	Manufacturer/Retailer	Date Purchased	Notes re: finishes, colors etc
1	Control	NA	NA	NA	NA
2	Ethafoam® HRC®	DNA	Manufactured and sample from Sealed Air	Sample Received Feb 2012	Black, 2" thick
3

Day 1: Preparing Equipment
Note: Document all stages with photography. Wear gloves at all times.

1. Gather all materials needed in advance. Make sure the distilled water is pH 7. Use NaOH if needed.
   
2. Label test tubes with the metal and material ID. Create a system for placement on trays if need be.
   
3. Treat all testing materials in the state they may be used (wash textiles, boards don’t need anything etc).
   
4. Wash the test tubes in warm water and then rinse in distilled water.
   
5. Preheat oven to 60 oC.
   
6. Set prep areas (see below for materials needed).
   

Day 2: Preparing Materials & Beginning Test

1. Processing Testing Materials
Note: This can be done the day before if left undisturbed
Materials needed: acetone, Kimwipes, scale, scissors/Xacto knife, materials to be tested

1. Wipe tools before and between materials.
   
2. Using a scale, measure out 3 – 2 gram amounts of materials to be tested (one for each metal).
   
3. Cut or delaminate each sample amount into small pieces to increase surface area exposed during test.
   
4. Store each sample in a sanitized location (a new polyethylene bag, or beaker, etc).
   

2. Test Tube Preparation
Materials needed: acetone, Kimwipes, tweezers, test tubes, vials, silicon stoppers, Xacto knife, pipette/dropper, distilled water

1. Wipe tools before and between materials.
   
2. Wipe test tubes, vials and silicon stoppers with acetone using a Kimwipe, tweezers.
   
3. Rinse inside of test tubes with acetone.
   
4. Place 2 g of materials to be tested into bottom of test tube.
   
5. Using a pipette/dropper/syringe, place .5 mL of distilled water in vial.
   
6. Gently lower vial into test tube making sure not to spill any water.
   
7. Cut a slit into silicon underside of stopper using Xacto knife (this is where the coupon will go).
   

3. Coupon Cleaning and Completing Test Preparation
Materials needed: acetone, Kimwipes, tweezers, Mylar, glass-bristle brushes, metal foils, scissors, gloves

1. Wipe tools before and between materials. Use new gloves with each material and then dispose after.
   
2. Set three stations with clean Mylar for surface and correct glass-bristle brush.
   
3. Cut metals into .5 cm x 1 cm coupons (specific weight?).
   
4. Polish and degrease each coupon with glass bristle brushes. Wear respirator mask when working with lead.
   
5. Wipe coupon with acetone and Kimwipe.
   
6. Coupons must not touch each other or any other surface. Immediately put coupons in slit in silicon stoppers as vertical as possible to reduce condensation from forming on the coupon.
   
7. Place corresponding silicon stopper with marked test tube (copper with copper etc).
   
8. Seal test tube with thread-seal tape.
   
9. Place Coroplast over filled test tube tray and.
   
10. Place filled test tube trays in oven and close door.
    

Day 3-31: In the oven
For the following 28 days, the oven should be monitored and a daily log kept with the temperature noted. If the temperature fluctuates drastically then the test may be corrupted. A table like the one below was used to record this information.

Day - Date	Time	Temperature/observations	Observer
1 - dd/mm/yyyy	00:00 PM	xx°C	CH
2 -
3 -

Day 31 – Gathering the results
Materials needed: clean work area, camera, tweezers,

1. Turn oven off and carefully open door. Note if any test tubes have broken or popped (rare).
2. Carefully remove test tube tray (may need piece of handling cloth, gloves) and place on work surface.
3. Keeping the test tubes vertical, inspect the materials for degradation and note observations.
4. Keeping the test tubes vertical remove the thread seal tape and the silicon stopper with the coupon inside.
5. Remove the coupon stopper, record observations and repeat for all test tubes.
6. Assign a result (P, TP, U) and record on following page along with the attached coupons. (Note: The test is corrupted if the control has corrosion.)

   P - Pass: suitable for long-term use; no change compared with control. Red/orange iridescence may appear on the copper control. Coupon should not have lost polished surface. Lead control coupon may acquire a purple hue. Aqueous corrosion has occurred on lead control coupon on a few occasions.)

   TP - Temporary Pass: suitable for indirect short term use; slight/questionable discoloration only, often seen along lower edge and sides or as a few localized small spots.

   U - Unsuitable for use: clearly visible corrosion or loss of polish, thin layer of corrosion over surface

7. Photograph or scan both sides of the coupon and make sure to keep a log of photos as to not get them confused. The physical coupons may continue to corrode so these images will be the best visual record of the test results. Keep the coupons in a table such as the one below.

ID#, Material	Coper	Lead	Silver	Result (P, TP, F)
1. Control	(physical coupon)	(physical coupon)	(physical coupon)	(Result)
2. Ethafoam® HRC®
3.

Heritage Conservation Centre Singapore (HCC) Protocol

The Heritage Conservation Centre (HCC), Singapore, carries out the “3-in-1” Oddy test, adapted from published protocols used at the British Museum (BM occasional paper number 111 2004). The first protocol undertaken at the HCC between 2009 and 2016 used a heat shrink tubing and ground glass stopper with nylon monofilament (Thickett and Lee 1995) and silver, lead and copper coupons were separated with glass beads. Since 2017, the second protocol uses a silicon stopper with cut slots to separate the coupons (Robinet and Thickett 2003). According to needs and experiences, HCC adopts two notable variations from the British museum protocol, which are triplicate testing and glassware cleaning procedure. In triplicate testing, three tubes containing the same sample are tested and an overall pass is indicated for the sample if two or more tubes pass the test. In the glassware cleaning procedure, an additional step in evaluating the glassware suitability of use is employed.

Second protocol since 2017

Sample preparation The thumb of rule is to prepare the material as they are used in exhibition or storage.

• For paints, adhesives and sealants, apply coating on a piece of cleaned Mylar and allow it to cure according to exhibition / storage use. After drying, scrape off 2 g of coating or roll the painted Mylar into the glass vessel.
• For fabric, cut, roll and secure it with a cotton thread. Washed fabric: For organic fabric, the fabric is boiled repeatedly until water runs clears. For synthetic fabric, the fibres are washed at 60° C until water runs clear.
• For foams, which are less dense, it may not be possible to squeeze 2 g into the tube. It is acceptable as long as the tube is sufficiently filled with the sample material, without touching the metal coupons.
• For glass cleaning agents, use a paper towel immersed with cleaning agent to clean the interior of the glass vessel.

Glassware cleaning procedure

• Fill glass tubes with cleaning solution of 2 % Decon 90 in deionised water and soak for 2 hours. Ensure no air bubble is trapped in glass tubes.
• After soaking, rinse the glass tubes with deionised water several times to remove any soap.
• Perform the ‘water test’. ‘Water test’ is carried out by overturning the deionised water filled tube. The glassware is considered clean when water flows smoothly down the glass surface, without water droplets clinging onto the glass surface within 10 sec.
• For glassware that failed the water test, repeat soaking in 5 % Decon 90 for 2 hours. Then perform the ‘water test’ again. If persistent residue is left in glass tubes, ultrasonicate these glass tubes for about 6 min in 2 % Decon 90. If residues cannot be removed, avoid using the tube.
• For those tubes that passed the ‘water test’, dry the glass tubes in the oven until use.

Preparation of coupons

• Prepare metal coupons in a fume cupboard or extractor.
• Wipe all metal trays and tools with acetone and cotton wool. A separate fibreglass bristle brush and metal tray is designated for each metal type to prevent cross-contamination.
• Measure and cut out a metal sheet.
• Place metal sheet over a glass block in its respective metal tray and use the respective fibreglass bristle to abrade one side of the metal sheet in two perpendicular directions.
• Continue the abrasion until the surface of the metal appears evenly polished.
• Turn the metal sheet to the other side and repeat the abrasion in two perpendicular directions.
• When the abrasion is satisfactory, wipe the metal surface with a clean and dry cotton wool to remove remnant fibreglass and metal particles. If particles remain, clean the remnants with 99,9 % purity acetone.
• Keep the metal coupons as flat as possible.
• Clean all tools with acetone after use.
• Using a scalpel, make three parallel slices at the bottom centre of the silicon stopper.
• With one hand, pinch the silicon stopper to open the cut and insert the metal coupon with tweezers.
• Start with inserting the lead coupon at the middle cut, followed by the silver and copper coupon at the auxiliary cuts.

Loading of samples

HCC Oddy Test Set Up

• Add deionised water into the fusion tubes (mini-glass tubes) and close the opening with a small plug of cotton wool. The size and porosity of the cotton wool plug shall be as uniform as possible according to past practices. Ensure that the cotton wool plug is dry and not wet with water.
• For highly absorbent materials like fabrics, add 0.6 ml deionised water. For low absorbent materials like paint, add 0.4 ml deionised water.
• Place the sample, fusion tube and metal coupons assembly into the glass tubes.
• Load three tubes without sample materials as negative controls.
• Ensure that the sample is not in contact with the metal coupons. Ensure the metal coupons are flat. Ensure that the metal coupons are neither touching the inner walls of the boiling tube nor each other.
• Leave the glass tubes in the oven at 60˚C for 28 days.

Metal coupon evaluation

• When removing the “Oddy test vessels” from the oven, check that the temperature is at 60° C. Check for any condensation of water vapour in the tubes upon cooling and whether the coupons are freely suspended.
• Remove the coupons from the tubes and place them on a white sheet of paper.
• Rate the metal coupons with P (pass), T (temporary) or U (unusable) relative to the control coupons.
• A pass is indicated if all coupons are rated P or T and a fail is indicated if any one coupon is rated U. Rate this for all triplicate tubes for each sample. Rate the sample pass if more than two tubes are rated pass.
• Photo-document the results.

Indianapolis Museum of Art at Newfields (IMA) Protocol

Previous Protocols: Download and view a pdf of a previous IMA protocol (see for the 2016 results): 2016 IMA protocol

Current Protocol: Download and view this PDF for a full version of the IMA’s most current protocol: 2020 IMA/Winterthur protocol

Or scroll down to see the 2020 protocol on this page.

Modified Indianapolis Museum of Art (IMA)/Winterthur Variant (Materials Working Group: Materials Testing & Standards Round Robin 2020- Oddy Test Protocol)

Introduction

This Oddy testing protocol is based on procedures that were initially developed at the Indianapolis Museum of Art by Dr. Gregory Dale Smith and Kathleen Kiefer. In 2015, the Winterthur Museum began using the IMA protocol but integrated minor modifications that were influenced by research and testing conducted by Elena Torok, Joelle Wickens, and Samantha Owens in 2014-2015. In 2018, after discussion at the Materials Working Group annual meeting in NY, additional minor modifications were made in advance of the 2019 MWG Round Robin to ensure all participating groups could obtain comparable results. In 2020, the protocol was edited to provide more detail and clarity and replace materials that were no longer commercially available. This document is currently maintained by Elena Torok.

I. Test Overview

1. All specifications for equipment and supplies needed to run this test are listed in Appendix 1. These materials should not be substituted. In the case that a substitution must occur (a vendor no longer exists, a product is discontinued, etc.), this substitution should be documented in test results.
2. All tests are run in duplicate, i.e. a test consists of two stoppered test tubes containing sample material with associated coupons. Each test is assigned an identifying number that is written on an adhesive label on the outside of the tube. Replicates are labeled “A” and “B”.
3. Negative controls, also in duplicate, are included with every group of materials tested. A unique identifying number is also assigned to each control, and replicates are also labeled “A” and “B”.
4. Samples should be prepared for testing according to the Material Sample Preparation Guide prepared by the Metropolitan Museum of Art (Appendix 2). If samples cannot be prepared according to these guidelines, this information should be documented in test results.
5. All testing details and results should be recorded in a custom-built database or spreadsheet prepared by the Metropolitan Museum of Art (Appendix 3).
6. Evaluation of metal coupons and the assignment of Permanent, Temporary, and Unsuitable ratings to sample materials is guided by the Glossary of Corrosion Phenomena compiled by the Metropolitan Museum of Art (Appendix 4).

II. Personal Protection Equipment (PPE)

1. Required PPE includes nitrile gloves, safety glasses, and a laboratory coat. A particle mask or respirator is also required for metal coupon preparation if access to a fume hood or some kind of modified enclosure is not possible.
2. No testing materials should be touched with ungloved hands, as skin oils can cause contamination of results.

III. Materials and Equipment A list with more detailed specifications can be found in Appendix 1.

1. Forced air oven
2. Borosilicate glass test tube, 75 mL, 200 mm (outer glassware)
3. Borosilicate glass culture tube, 0.75 mL, 50 mm (inner glassware)
4. Versilic peroxide-cured silicone stopper, size 27D
5. Parafilm ® M
6. Poly-temp PTFE tape
7. Metal coupons (silver, lead, and copper), each 10 mm x 25 mm
8. 3200 grit Micromesh
9. PCC-54 Enzymatic Detergent Concentrate
10. Deionized water
11. Acetone
12. Kim wipes
13. Nitrile gloves 3
14. Glass plate
15. Sample (approximately 2 g)

IV. Pre-Testing Washing and Cleaning Methods

1. Glass test tubes should be cleaned before testing using 5% PCC-54 Enzymatic Detergent Concentrate in water. Test tubes should be soaked in this solution for at least 20 minutes, rinsed thoroughly with water until suds are gone, and then triple rinsed with deionized water. Test tubes should be left to air dry, and must be completely dry before coupons, sample, etc. are inserted.
2. Glass culture tubes should be cleaned before testing using acetone.
3. Stoppers should be rinsed before testing with deionized water, and then wiped down using acetone on a Kimwipe.

V. Metal Coupon Preparation

1. Cut metal foils to 10 mm x 35 mm coupons using scissors that have been cleaned with acetone.
2. Polish both sides of each coupon evenly using 3200 grit Micromesh. Polishing should be done horizontally across the coupon; while holding one end of the coupon against the glass plate, polish from the center of the coupon towards the end, and then rotate to repeat this action to the other end. Flip the coupon over and repeat again.
   • The same piece of Micromesh can be used to polish two coupons of the same metal but should never be used to polish coupons of a different metal.
   • The glass plate should be cleaned with acetone between polishings of different types of metals.
   • If necessary, for large sample runs, the silver and copper coupons can be polished and sealed in a clean glass jar and left overnight. However, the lead coupons must be polished on the day the test is to be set up and begun.
3. Use tweezers to dip each coupon in an acetone bath. Remove coupon from the bath and immediately pat dry using a Kim wipe. Coupons should not be left to soak in the acetone bath for prolonged periods of time or allowed to air dry.

VI. Stopper Preparation

1. Cut three parallel 10 mm x ~5 mm deep slits in the small end of each stopper using a scalpel blade that has been cleaned with acetone.
2. Stoppers may be reused in testing ONLY if their prior use was in a test tube that contained a sample that was evaluated to be Permanent or Temporary. Stoppers used with samples evaluated to be Unsuitable should be discarded. Stoppers that begin to show any evidence material breakdown (discoloration, shedding, etc.) should also be discarded.

VII. Sample Preparation

1. Prepare 2.0 g of sample material.
2. Sample preparation will vary by sample type and should be prepared according to established MMA procedures found in Appendix 2.

VIII. Test Tube Preparation and Assembly

1. Place the sample in the base of the 75 mL test tube.
2. Fill the culture tube with ~0.65 mL of deionized water using a pipette. Place the culture tube in the base of the test tube, next to the sample. From this point forward, care must be taken to limit rapid movement of the test tube, as water can easily spill from the culture tube.
3. Use tweezers that have been cleaned with acetone to insert each of the three coupons (Cu, Ag, Pb) into a slit in the small end of the stopper. Slits can be opened by pressing the curved sides of the stopper. Place the Pb coupon in the middle slit.
4. Insert the small end of the stopper (with coupons) into the top of the test tube. Push the stopper in tightly.
5. Wrap approximately 10 inches of Poly-temp PTFE tape around the top of the test tube and stopper. The wrapping needs to be tight, because as the test tube heats up, the stopper will be pushed out of the tube. Wrapping the tape tightly will help keep the stopper in place.
6. Wrap Parafilm over and around the PTFE tape-covered stopper and test tube top. Again, ensure wrapping is tight and secure.
7. Label the exterior of each test tube with an adhesive white label to identify the sample inside and the testing start date.
8. Place test tubes in a test tube holder or large glass beaker so they can remain as upright and vertical as possible during testing.

IX. Testing

1. Place test tubes in a forced air oven that has been pre-heated to 60oC.
2. Leave test tubes in the oven for 28 days.
   • In the first few hours of testing, check to make sure no stoppers have popped open. If a stopper has popped but is still generally resting in its appropriate position at the top of the test tube, push it back in and re-secure the area with more PTFE tape and Parafilm. If the stopper has popped out of the test tube entirely and is resting on the shelf or floor of the oven, the test tube should be re-prepared. Any type of stopper popping event should be noted in results.
   • Every few days, a quick visual inspection of test tubes should be performed to confirm that approximately the same level of water is still present in the culture tubes. If water levels are low or non-existent, there is likely a leak between stopper and test tube. In this event, remove the test tube from the oven, remove the stopper, add more water to the culture tube, re-seal the 5 stopper back in its appropriate position, and then place the test tube back in the oven. Any type of water loss event should be noted in results.

X. Assessment at Completion of Testing

1. After 28 days in the oven, remove test tubes and allow them to cool to room temperature.
2. Identify a clean, flat surface of the lab that has access to strong and consistent indoor lighting. Gather an Optivisor or magnifying loop and a printed copy of the MMA’s Glossary of Corrosion Phenomena (Appendix 4), which will be used as reference while conducting coupon examination.
3. Assessment involves rating all non-control coupons as compared to the control coupons. Ratings are assigned to each metal as instructed in the MMA’s Glossary of Corrosion Phenomena (Appendix 4). In general, all coupons will receive one of three of the following ratings:
   • “Permanent” rating: The material tested may be used indefinitely in the presence of art. ▪ Coupons look similar to the controls.
     • Copper: Very slight reddening
     • Silver: Thin white haze
     • Lead: Slight darkening
     • For silver, remnants of polishing compounds from some manufacturers can develop or appear as white splotches. This stock is generally returned to the manufacturer, however, if it makes it into a test, the white splotches are ignored.
   • “Temporary” rating: The material is safe for use near but not in contact with art for up to six months.
     • Copper: Slight reddening, yellowing, or rainbow-like color change, formation of up to 20 black spots
     • Silver: Slight yellowing, purpling, or darkening.
     • Lead: Darkening, yellow/olive tarnish, haze from slight crystal formation over the entire coupon, or heavier crystal formation at the interface with the coupon holder.
   • “Unsuitable” rating: The material should not be used in contact with or near art and another material should be found.
     • Copper: Severe blackening or severe reddening or matte-textured surface.
     • Silver: Severe color change to dark purple, yellow, or black.
     • Lead: White fluffy crystal formation of any size.
4. To remove coupons from a test tube, first remove the Parafilm and PTFE tape and then carefully pull the stopper out. Flip the stopper over (large side down, with coupons pointing vertically upward) onto a clean, flat surface. Squeeze the sides of the stopper to open the slits, and use clean tweezers to carefully remove Cu, Ag, and Pb coupons. Place coupons on a white piece of paper.
5. Open control test tubes and examine control coupons first. If coupons in both test tubes are minimally corroded, meaning that the corrosion phenomena observed are at or below the threshold of those rated “P” in the MMA’s Glossary of Corrosion Phenomena (Appendix 4), the control test is considered valid. If corrosion phenomena observed on any metal coupon in one or both control jars are rated “T”, the control test is not valid. The corrosion phenomena present on the controls is still recorded in the test record, and individual metals for each associated sample test are described and rated according to the corrosion phenomena observed, but overall ratings for all sample tests in the batch must be retested.
6. Examine coupons from sample test tubes next. The corrosion phenomena observed on each coupon below the area that was inserted into the stopper are compared to the MMA’s Glossary of Corrosion Phenomena (Appendix 4) and described separately for replicates “A” and “B” in the test record. Corrosion phenomena not present in the glossary should nevertheless be described and may be added to the glossary. The lowest of the ratings assigned to the three metals in the test is also the overall rating assigned to the material. In the event that there are moderate differences in the same corrosion phenomenon on “A” and “B” replicates, as long as the rating for both levels is still the same, the result is valid. However, if the more extreme corrosion pushes one coupon into the next rating category, or if the replicates exhibit different types of corrosion phenomena, then the sample should be retested.

XI. Disassembly and Reuse of Test Materials

1. After testing is complete, disassemble tests and clean according to instructions in Section IV above.
2. Samples should be discarded.
3. Glassware should be reused in future testing, so long as it does not have breaks, cracks, or other signs of deterioration.
4. Stoppers can be reused in future testing, but only if they were associated with tests that yielded “P” or “T” results. Stoppers should not be reused if associated with a test that yielded “U” results OR are showing signs of deterioration (discoloration, shedding, etc.).

XII. Photographing Oddy Test Coupons

1. After evaluation, Oddy test coupons should be photographed according to established MMA standards. Test results and images should be uploaded to the AIC Wiki.
2. To ensure standardization in the 2020 Round Robin, all participants should mail coupons to Alayna Bone at the MMA for photography. Coupons should be individually placed in corrosion intercept bags prior to mailing.

Appendix 1. Materials and Equipment

Materials Used in IMA/Winterthur Oddy Testing (figures last updated February 2020)
ITEM	VENDOR	QUANTITY	COST
Forced Air Oven, 104 L (3.7 cubic feet)	VWR 89511-412	1	$2,871.13
Acetone, high purity (≥99.8%), 1L	Sigma Aldrich 34850	1	$84.30
PCC-54 Enzymatic Detergent Concentrate, 3L bottle	Thermo Scientific 72288	1	$86.00
Alfa Aesar silver foil, 0.127 mm (0.005 in) thick, annealed, 99.9% (metals basis), 100 x 100 mm	VWR AA11440-GH	Varies according to number of tests needed	$82.86 each
Alfa Aesar copper foil, 0.127 mm (0.005 in) thick, annealed, 99.9% (metals basis), 20 cm x 20 cm	VWR AA13380-CU	Varies according to number of tests needed	$42.74 each
Alfa Aesar lead foil, 0.1 mm (0.004 in) thick, >99.998% (metals basis), Puratronic®, 50 x 50 mm	VWR AA12051-FI	Varies according to number of tests needed	$96.22 each
Avery White Laser Mailing Labels (30 labels, 1 in. x 2 5/8 in. per sheet)	Avery 5260	1	$17.99
Stainless steel specimen forceps, 305 mm, 12” long	VWR 82027-382	1	$40.28
Kimax test tubes, Type 1 Class A borosilicate glass, 75 mL, 25 x 200 mm OR VWR test tubes, Type 1 Class A borosilicate glass, 75 mL, 25 x 200 mm	VWR 89001-432 VWR 10545-930	1 pack of 24 1 pack of 48	$85.70 $81.91
Saint Gobain - Versilic silicone stoppers, size 27D	LabPure D1069813
Culture tubes, disposable, borosilicate glass, 0.75 mL, 6 x 50 mm	VWR 47729-566	1 case of 2,000	$266.20

Appendix 2. Material Sample Preparation Guide

Material	Proposed Cutting Method
Board - composite (eg. Corian, drywall)	Cut with universal blade band saw into 0.5” cubes. Use utility knife to produce smaller pieces to make 2.0g.
Board - natural (eg. wood, cotton)
Board - plastic/polymeric/synthetic
Carpet - natural/non-synthetic fiber	Cut with clean scissors or utility knife into 1 x 1” squares. To reach 2.0 g, cut pieces that represent the sample’s composition—example: the correct ratio of carpet material, blended fibers in carpet, and base of carpet.
Carpet - plastic/polymeric/synthetic fiber
Coating- floor (e.g. stain, anti-wear, anti-slip)	Follow manufacturer’s instructions regarding dilution; if to be used dry, paint out on Mylar® and cure per manufacturer’s guidelines; if to be used wet, use 0.5mL of liquid in lieu of water.
Coating - grease, oil, wax	Into a 5mL beaker, weigh 2.0 g of sample. Carefully place into the sample jar. Other borosilicate vessels that fit are acceptable as long as they are no more than 4cm tall.
Coating - paint & primer	Paint material onto a Mylar® sheet and spread to a thickness that reflects how it will be used in the museum. Cure the material according to manufacturer’s instructions. After curing, cut the painted Mylar® into 1.5” wide strips and weigh to 2.0 g, taking the weight of the Mylar® into account by subtracting it from the total sample weight. Put a small piece of Mylar® at the bottom of the jar if there’s concern about the material sticking to the glass. Roll the sample strips into a coil with the sample material facing inward, and place in the bottom of the jar.
Coating - protective (e.g. anti-UV, -abrasion, -tarnish)
Fabric - batting & padding	Cut material with clean fabric scissors into 1 x 1” squares. To reach 2.0 g, cut small segments from a 1” square.
Fabric - book cloth
Fabric - exhibition/woven
Fiber or Thread	Cut the length of sample that weighs 2.0 g. Wind it loosely and neatly around two gloved fingers, remove, and place in the bottom of the sample jar.
Inorganic - (e.g. fillers, salts, rocks)	Keep the sample as is or prepare it as it would be used in the museum. For example, if you are testing salts, do not grind them further unless that’s how they are used in the museum setting. Weight 2.0 g of sample.
Metal - mechanical fastener	Place whole fastener in jar.
Paper-based (e.g. folder, cardboard, sheet)	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut pieces from a 1” square.
Paper-based, Filled (e.g. fillers such as silica gel, zeolites, alumina)
Paste - filler/binder mixture (e.g. plaster, acrylic spackle, non-paint)	Extrude onto a Mylar® sheet. Spread to a thickness that reflects how it will be used in the museum setting. Cure material per manufacturer’s suggestion. After cured, peel the material from the Mylar® if possible and weigh to 2.0 g. If the material cannot be freed from the Mylar®, remove excess Mylar® and weigh the material to 2.00 g, taking the weight of the Mylar® into account by subtracting it from the total sample weight.
Polymer - adhesive - caulk or sealant
Polymer - adhesive - glues - liquid (e.g. acrylics, wood glues, starches)	Extrude adhesives onto Mylar® sheeting in a thickness that reflects the actual material application thickness. Cure per manufacturer’s instructions. Cut the sample into 1 x 1” squares. Weigh the dried material on Mylar®, taking into account the weight of the Mylar® attached to the sample. To reach 2.0 g, cut pieces from a 1 x 1” square.
Polymer - adhesive - heat activated (e.g. hot melt, heat set)	Extrude 2” strips of melted material onto aluminum foil. Allow to cool. Peel from aluminum foil and weigh out 2.0 g of sample. If material does not remove from foil, repeat on Mylar® and account for the weight of the Mylar® in weighing the sample.
Polymer - adhesive - pressure-sensitive	Cut 2” lengths of tape, taping the adhesive sides, to the backed sides to form a small 2.0 g block of tape. Place the sample onto Mylar® to protect the jar from the adhesive.
Polymer - adhesive tape - single sided
Polymer - adhesive tape - double sided	Fold the tape onto itself “accordion style” every 2” while removing the backing. Put 2.00 g sample on a piece of Mylar® to protect the jar from the adhesive, and carefully place in the bottom of the jar.
Polymer - block/bulk/pellet	If material comes in a block, cut into 0.5” cubes using a band-saw. If the material comes in small pellets that fit in the sample jar, use whole uncut pellets. To reach 2.0 g, shave material from one cube or pellet using a utility knife.
Polymer - foam - building insulation	For dense foam, cut with universal band saw into 0.5” cubes. To reach 2.0 g, remove material from one cube using a utility knife. For soft foams, cut material with clean scissors into a 1.5” wide strip that weighs 2.0 g. Compress the strip into a roll, and insert into the bottom of the jar. Make sure the foam does NOT touch the metal coupons when it expands.
Polymer - foam - non building insulation	For dense foam, cut with universal band saw into 0.5” cubes. To reach 2.0 g, shave any excess material on only one cube using a utility knife. For soft foams, cut material with scissors into a 1.5” wide strip that weighs 2.00 g. Compress the strip into a roll, and insert into the bottom of the jar. Make sure the foam does NOT touch the metal coupons when it expands.
Polymer - foam sealant	Cut material with clean scissors into a 1.5” wide strip that weighs 2.0 g. Compress the strip into a roll, and insert into the bottom of the jar. Make sure the foam does NOT touch the metal coupons when it expands.
Polymer - gasket	Cut material with clean scissors into 2” length strips. Polymer - glove Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut pieces from a 1” square.
Polymer - membrane (<1mm thick)	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut pieces from a 1” square.
Polymer - sheet (>1mm thick)	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut a minimal amount of strips from a 1” square.

Appendix 3. Test Record Spreadsheet This appendix is supplied separately as an Excel Document. Digital copies are also are available from Julia Sybalsky, jsybalsky@amnh.org.

Appendix 4. Glossary of Corrosion Phenomena

A summary of corrosion phenomena is provided below, along with their associated ratings. For Round Robin 2020, the illustrated glossary will be supplied separately to testers, and will be available from Eric Brietung, Eric.Breitung@metmuseum.org. In future versions of the protocol, it will be included here.

Copper

• Very slight red tarnish (P/T)
• Slight red tarnish (T)
• Red tarnish (T)
• Extreme red tarnish (T)
• Rainbow tarnish (T)
• Light haze (T): specular reflection at most angles. Diffuse at glancing angles.
• Heavy haze (U): diffuse reflection at any angle
• Black corrosion spots (T/U)

Silver

• White film/haze (NA/T): NA if it looks like a splotchy manufacturer defect. T if it looks like corrosion from the sample.
• Orange/yellow film/haze (NA/T): NA if it looks like manufacturer defect. T if it looks like corrosion from the sample.
• Yellow tarnish (T)
• Rainbow tarnish (T/U)
• Light purple tarnish (T/U)
• Heavy purple tarnish (U)
• Black tarnish (U)

Lead

• Very slight darkening (P/T)
• Slight darkening (T)
• Darkening (T)
• Extreme darkening (T)
• Blue tarnish (T)
• Blue compacted corrosion (T)
• Rainbow tarnish (T)
• Violet tarnish (T)
• Thin orange compacted corrosion (T)
• Thick orange compacted corrosion (U)
• Thick/light white compacted corrosion (T/U) - previously called ‘light white haze)’
• Thin Yellow/green compacted corrosion (T)
• Thick Yellow/green compacted corrosion (U)
• Fluffy white crystals (U)

Metropolitan Museum of Art (MMA) Protocol

Current Protocol:
Download and view this PDF for a full version of the MMA’s most current protocol: 20211201_OT.

This protocol has been updated to replace the 3D printed nylon coupon holders with water-jet cut stainless steel coupon holders. For more information: Updating The Metropolitan Museum of Art's Oddy Test Protocol: Reducing costs and waste with a stainless steel coupon hanger

Current photos of scored coupons and commonly observed corrosion phenomena are documented in the links below. All coupon images in these documents are linked to their original high-resolution photographs stored on the AIC wiki:
Copper Corrosion Library
Silver Corrosion Library
Lead Corrosion Library

Previous corrosion libraries used between March 2018 and September 2020 are located in the following links: Copper Coupon Library, Silver Coupon Library, and Lead Coupon Library.

The Met’s previous versions, that incorporated silicone stoppers (20160416_OT), and nylon holders (20190226_OT) are also available for download: 20160416_OT
20190226_OT

Minor Variations to protocols 20160416_OT, 20190226_OT (20160620_OT through 20191213_B_OT), and 20211201_OT can be found in the following document: Oddy Test Methods Chart.

Current Version: 20211201_OT
11 May 2022
Buscarino, I. C., Bone, A. C., Stephens, C. H., and Breitung, E. M.

This method adopts aspects from the protocol published by The British Museum, where test tubes are fitted with silicone stoppers holding three metal coupons, and the Met’s original three in one jar version , where metals are hung from the rim of a beaker inside of a screw-top jar. In both cases, the corrosion states of the coupons after 28 days of aging at elevated temperatures and humidity in the presence of an unknown material are used to determine the appropriateness of a material for use in close proximity to cultural heritage materials.

The Met’s previous versions 20160416_OT and 20190226_OT, which are downloadable from the AIC’s Oddy test wiki site, incorporated silicone stoppers or nylon coupon holders, respectively, pressed into the neck of screw-top Pyrex™ jars. We observed significant inconsistencies in stopper quality and production time, which lead us to identify replacement options.

The current version 20211201_OT, which is downloadable from the AIC’s Oddy test wiki site, replaces the 3D printed nylon coupon holders with reusable water-jet cut stainless steel holders that fit into the neck of screw-top Pyrex™ jars. This new method retains the repeatability improvements made with method 20190226_OT and reduces long-term waste. However, based on some test results, the silver coupon is very slightly less sensitive to sulfides when using the stainless steel holder. The difference does not appear to be significant enough to warrant the continued use of nylon holders given the cost and reusability benefits provided by the stainless steel holders. The nylon holders will remain available for purchase on Shapeways for those using the Oddy test to evaluate materials intended for use with silver collections, where the sensitivity of the silver coupon is paramount.
This document includes written instructions and links to video demonstrations of the method. Each change has been labeled as a new version of the test using the following format YEARMODA_OT indicating the year (YEAR), month (MO), and date (DA) the modification was implemented. A list of versions correlating to results being published on the AIC Oddy Test wiki site is available here.

Outline:
I. Personal Protection Equipment (PPE)
II. Washing Methods
III. Metal Coupon Preparation
IV. Jar preparation and assembly
V. Assessment at completion of testing
VI. Photographing Oddy Test Coupons
VII. Materials and Supplies
VIII. Oddy Test Material Sample Preparation Guide
IX. Oddy Test Form

I. Personal Protection Equipment (PPE): Nitrile gloves, safety glasses, and a laboratory coat are worn throughout this procedure. Hands are washed with soap and warm water prior to donning gloves to remove oils. Care is taken to always handle the metal coupons (copper [Cu], lead [Pb], or silver [Ag]) with tweezers while wearing clean nitrile gloves, as handling coupons with dirty or oily hands can cause coupon contamination. Out of a small range of gloves, Freeform® SE blue powder-free nitrile gloves performed best in the Met’s Oddy test and are worn throughout the procedure.

II. Washing Methods: Outlined below are two different washing methods. The hand washing method was used April 2016 to July 2017. The dishwasher method began in July 2017 and is our current washing method.

Note: New components are always washed before using. New Stainless steel holders should be hand washed with Micro-90 Lab Cleaner following the Hand Washing Method before using the first time. Subsequently either the Hand Washing Method of the Dishwasher Method is acceptable. Used components are not always reused. Lids and o-rings from unsuitable test jars are NOT reused. O-rings from temporary test jars are NOT reused. Lids and o-rings from permanent test jars and lids from temporary test jars can be reused. Lids from temporary test jars are tracked and after a lid has been in a temporary test up to four times, it is no longer reused. Once washed, stainless steel holders can be reused regardless of prior test results. These practices were established to avoid the possibility of contamination from one test to another. All used materials are separated by type and test result and saved for potential future use if it is established that cross contamination is not an issue.

A) Dishwasher Method Used June 6, 2017-current (method 20170606_OT)

Using Lancer 815 LX Dishwasher

Glassware: Mechanically remove all materials from jar. Place each jar over a spindle jet. The wash cycle includes the following steps:

Prewash	Rinse for 2 min.* with 60°C water
Wash (base)	Rinse with 96 mL of NaOH in 12 L of water at 40°C for 2 min.*
Rinse A	Rinse for 2 min. with unheated water.
Acid Rinse	Rinse with 96 mL of Phosphoric Acid in 12 L of unheated water for 2 min.
Rinse B	Rinse for 3 min. with unheated water.
Rinse C	Rinse for 3 min. with unheated water.
Purified Water Rinse A	Rinse for 3 min. with unheated 15 MΩ-deionized water.
Purified Water Rinse B	Rinse for 1 min.* with 60°C 15 MΩ-deionized water.

*When water is being heated, it is recycled within the chamber until it reaches temperature making the times listed much shorter than the actual cycle time. After the washer reaches the prescribed temperature, it runs for the programmed amount of time. The full wash cycle requires approximately 1.75 hours. Detergents are not currently used, however, testing is underway to determine if their use improves consistency of results.

Washed glassware placed in a 60°C oven for drying and storage.

Viton™ o-rings, stainless steel coupon holders, and lids: Place on flat stainless steel mesh rack. Lids are placed upright and are weighted with a stainless steel mesh screen to inhibit flipping. The wash cycle includes the following steps:

Prewash	Rinse for 2 min.* with 80°C water
Rinse A	Rinse for 5 min. with unheated water.
Rinse B	Rinse for 1 min.* with 80°C water.
Purified Water Rinse A	Rinse for 1 min. with unheated 15 MΩ-deionized water.
Purified Water Rinse B	Rinse for 1 min.* with 60°C 15 MΩ-deionized water.

*When water is being heated, it is recycled within the chamber until it reaches temperature making the times listed much shorter than the actual cycle time. After the washer reaches the prescribed temperature, it runs for the programmed amount of time. The full wash cycle requires approximately 2.5 hours. Detergents are not currently used, however, testing is underway to determine if their use improves consistency of results.

Washed o-rings, lids, and silicone stoppers are dried and stored in a 60°C oven.

Vials: KIMAX™ vials are washed by hand.

1. Dirty vials are placed in a 50 mL Pyrex® beaker, and a disposable glass pipet is used to deliver solutions into the vials. Soak vials with Micro 90 Lab cleaner for at least 24 hours (1% solution in tap water). Rinse 3 times with tap water. Soak in room temperature aqueous sodium hydroxide (NaOH) bath with a pH of 12 for at least 15 hours (overnight). Use 10” stainless steel tongs for delivering and retrieving items from the baths. Thick nitrile gloves, safety glasses, and a laboratory coat are required.

   a. Base bath preparation (yields 1 L): Add 0.40 g NaOH (s) to 1 L of deionized H2O. Check that the pH reads 12 on the pH indicator strip. The base bath is in a glass beaker contained in a lidded polypropylene 12 quart container within a secondary polypropylene drip container.
   

2. Rinse with hot tap water then place in a hydrochloric acid (HCl) bath with a pH of 2 for at least 15 hours (overnight). Thick nitrile gloves, safety glasses, and a laboratory coat are required.
   

   a. Acid bath preparation (yields 1 L): Slowly add 0.8 mL HCl (37% w/w; 1.2 g/mL density) to 250 mL of deionized H2O. Add the remaining 750 mL of deionized H2O. Check that the pH reads 2 on the pH indicator strip. The acid bath is in a glass beaker contained in a lidded polypropylene 12 quart container within a secondary polypropylene drip container.
   

   b. Rinse three times with hot tap water then rinse three times with 18.2 mΩ-deionized water.
   

   c. Dry in an oven, right side up, at 60°C.
   
   

Figure 1: Base and acid baths in secondary containers.

B) Hand-washing Method Used April 2016-May 2017 (method 20160416_OT)

Glassware Preparation:

1. Wash with Micro-90 Lab Cleaner (1% solution in tap water) using a laboratory cleaning brush and tap water.
   
2. Rinse 3 times with hot tap water.
   
3. Soak in room temperature aqueous sodium hydroxide (NaOH) bath with a pH of 12 for at least 15 hours (overnight). Use pipets to deliver the solutions into the small vials. Use 10” stainless steel tongs for delivering and retrieving items from the baths. Thick nitrile gloves, safety glasses, and a laboratory coat are required.
   

   a. Base bath preparation (yields 7 L): Add 3.0 g NaOH (s) to 7.5 L of deionized H2O. Check that the pH reads 12 on the pH indicator strip. The base bath is contained in a lidded polypropylene 12 quart container within a secondary polypropylene drip container.
   

4. Rinse with hot tap water then placed in a hydrochloric acid (HCl) bath with a pH of 2 for at least 15 hours (overnight). Thick nitrile gloves, safety glasses, and a laboratory coat are required.
   

   a. Acid bath preparation (yields 7 L): Slowly add ~6 mL HCl (37% w/w; 1.2 g/mL density) to 2 L of deionized H2O. Add the remaining 5 L of deionized H2O. Check that the pH reads 2 on the pH indicator strip. The acid bath is contained in a lidded polypropylene 12 quart container within a secondary polypropylene drip container.

5. Rinse three times with hot tap water then rinse three times with 18.2 mΩ-deionized water.
   
6. Dry in an oven, right side up, at 60°C.
   
   

Viton™ o-rings, stainless steel holders, and lids:

1. Wash Viton™ o-rings, stainless steel holders, and lids in a Micro-90 Lab Cleaner solution (1% in tap water) by dipping in cleaning solution and rubbing with gloved hands or a clean sponge. Do NOT soak for any length of time in Micro-90 Lab Cleaner solution.
   
2. Rinse 3 times with hot tap water and 3 times with 18.2 MΩ-deionized water.
   
3. Store in oven at 60°C.
   
   

KIMAX™ Vials: Same as instructions outlined in the dishwashing method section II-A above.

III. Metal Coupon Preparation

1. Measure and cut high purity (99.998% or higher) metals (Ag, and Cu) into coupons measuring 0.8 cm x 2.5 cm. Cut Pb into strips that are 10 cm long by 0.8(x) cm wide, with x being the number of skinny strips you want. Each skinny strip yields 4 coupons. Cutting large strips of lead before sanding and then cutting them down after sanding makes the sanding process quicker and more efficient.

   a. Use a dedicated pair of scissors for each metal.

   b. An in-contact variant of this test is used to assess materials that are expected to be in physical contact with the art. The in-contact test can be run on its own without hanging materials or in addition to the standard protocol in the same jars as the hanging coupons. For the in-contact version, measure and cut the Ag and Cu into 0.8 x 1.25 cm coupons. These in-contact coupons are half the size of the standard ones. Cut the Pb into 10 cm long by 0.8(x) cm wide, with x being the number of skinny strips needed. Each skinny strip yields 8 coupons. Continue with the same sanding and washing techniques as the standard protocol.

Figure 2: Left: a properly sanded lead coupon. Middle: a partially over-sanded lead coupon. Right: a fully over-sanded shiny lead coupon.

2. Place a 12” x 12” flat glass plate inside the filtration box, and place the un-sanded 10 cm by 0.8(x) cm lead strips on top of the glass plate. The strips should be made as flat as possible before sanding. The metal is very soft and flexible, so it ripples easily. Any ripples or creases will make it more difficult to achieve an even texture after sanding. Cut a 2 in square piece of 3200 grit Micromesh™ sand paper and fold it in half twice so that it forms a 1 in square with grit on both sides. To sand, hold down the end of one lead strip and sand from the center of the strip to the end away from the user using even light pressure (Click here for video). While sanding, hold the Micromesh™ under one thumb so that pad of the thumb is flat when applying pressure and covers the entire width of the lead strip. Avoid using the tip of the thumb or pressing part of the thumbnail into the Micromesh™. Change the position to an unused portion of the Micromesh™ every 15-20 strokes. Every stroke should be linear and run all the way from the middle of the strip to the far end. Approximately 45 strokes will properly sand a single section of lead. Once the first section is sanded, rotate the strip 180 degrees and sand the second half of the same side, then flip the strip and sand the other side using the same process.

   a. If the lead strips visibly stretch longer than 10 cm, too much pressure is being applied while sanding. The goal is to remove the native oxide with minimal pressure. Hanging large images of over-sanded and correctly sanded lead coupons in the preparation area is recommended for reference. A correctly sanded lead coupon is lighter in shade than the un-sanded lead and has a consistent overall texture with no shiny patches of specular reflection Consistent sanding is critical for producing reproducible test coupons. The goal is to remove the native oxide with minimal pressure. Hanging large images of over-sanded and correctly sanded lead coupons in the preparation area is recommended for reference. See Figure 2 (right) for an example of properly sanded lead and shiny over-sanded lead. The sanding process is completed in a homemade ‘filtration box’ with ULPA filtration (Click here for video). The box is wiped clean after each sanding session, properly disposing of the contaminated wipes.

Figure 3: Freshly cut and sanded (lead only) metal coupons.

b. Sand lead coupons immediately before inserting into jars to minimize re-oxidation of the surface.

3. Fill and label 2 small beakers with acetone to soak copper and silver coupons in, keeping the different metals separate. Using tweezers, remove the coupons from the acetone and wipe dry with a Kimwipe® making sure not to touch the metal surface with gloves. Next, in new beakers soak the coupons in fresh HPLC grade isopropanol. Remove from beakers and wipe dry with a Kimwipe® (Click here for video). Collect rinse solutions and disposed of as hazardous waste.
4. After sanding 10 cm long lead strips, rinse each side with a Kimwipe® dipped in acetone. Repeat until the Kimwipe® wipes clean. Next dip a Kimwipe® in isopropanol and wipe each side of the lead strip. Repeat. (Click here for video). Cut the large lead strip into skinny 0.8 cm x 10 cm strips. Cut each 0.8 cm lead strip into four 0.8 cm x 2.5 cm coupons.

a. Cut lead for the in-contact variant to 0.8 cm x 1.25 cm half-size coupons.

5. After polishing and rinsing, dispose of Mylar™, Pb-contaminated gloves, and sandpaper as lead-contaminated hazardous waste.
6. All metals are stored immediately upon receipt from the supplier within at least one Intercept® Ziploc®-style bag. Ideally both sides of the bag are composed of the Intercept material rather than using the style with a transparent window.

IV. Jar preparation and assembly

1. Run all tests in duplicate, including controls. Produce one set of controls for each group of tests. In other words, if 15 materials are being tested on Monday, one set of controls is required. A new set of controls is required for the next group of Oddy tests that are prepared on Tuesday.
2. To prepare one jar, place a sheet of weighing paper on the scale and tare to zero. Weigh 2g of test sample material on the paper and load into a 100 mL borosilicate jar (Kimble™ KIMAX™ GL 45 Media/Storage Bottles, Product # 02-542A, 100mL) along with a borosilicate mini-test tube (Kimble™ KIMAX™ Reusable Borosilicate Glass Tubes with Plain End, Product #14-925B, 0.7mL) containing 0.5mL 18.2 MΩ-deionized water. Dose 18.2 MΩ water into the mini-test tube using a recently calibrated micropipette.

   a. See Section VIII for a sample preparation guide.

   b. Each control jar contains 0.5 mL of water in the KIMAX™ test tube as well as the metal coupons folded over a coupon holder. No other material is placed in the jar.

3. To a pre-washed stainless steel coupon holder, attach the metal coupons by bending the coupon with tweezers 5-7mm from one end and crimping it onto the holder (see Figure 4). Insert the coupon holder into the mouth of the jar.

   a. Make sure coupons do not come into contact with each other, the jar, or test material.

   b. For the in-contact variant, using tweezers, on each coupon fold over a 1-2 mm of one corner. Make sure that the test material in the jar lays as flat as possible and place a Cu, Ag, and Pb coupon on top of the material so that the folded triangle flap of each coupon faces up toward the mouth of the jar and the smooth side of the coupons is facing down toward the bottom of the jar. Place the coupons so that smooth side is fully in contact with the sample material and none of the coupons are touching each other or the glass sides of the jar. In control jars, place the coupons on the bottom of the jar in the same orientation as sample jars.

Figures 4 & 5: the triangle-configured water-jet cut stainless steel holder from the side(left) and the top (right).	Figures 6 & 7: Left: crimping the Cu coupon onto the holder using tweezers. Right: A coupon holder with Cu, Ag, and Pb coupons attached.
Figures 8, 9, & 10: Left: a coupon holder placed in the neck of a sample jar. Center and Right: A sealed sample jar with hanger, coupons, test material, water and vial.

4. Insert a Viton o-ring into each lid and lightly screw the lids onto the jars. Tighten lids to a torque of 4 Nm using a torque wrench fitted with the custom socket.
5. Weigh jars and record values.
6. Place in oven leaving as much space between jars as possible for air circulation, standing upright.

Figure 11 & 12: 3D printed torque wrench socket produced to fit GL45 cap and CDI 1502MRMH-QR torque wrench (2.8-16.4 Nm range) used for tightening lids consistently.

7. Leave jars in oven at 60°C for 60 minutes. Remove jars and re-tighten lids to a torque of 4 Nm while warm using a torque wrench fitted with the custom socket.
8. Return jars to the oven and age at 60 ± 1.5 °C for 28 days.

V. Assessment at completion of testing

1. After 28 days in the oven, remove jars and allow to cool to room temperature.
2. Record weights of each jar. Compare to the pre-aged weights to determine whether each vessel was sealed during the experiment. A loss greater than 25% of mass (25% of 0.5 grams, or a loss of more than 0.13 grams) is considered a system failure, and the experiment is repeated.
3. Open jars and lift the coupon holders out of the jars. Remove coupons from the coupon holders using tweezers.
4. Unfold the coupon where it was crimped over the coupon holder. Scribe the inside of each coupon across the width of the coupon where it met with the holder using a dissection needle. Press the coupons flat using two blocks of polished flat stainless steel, aluminum, or glass. Place the coupons on a fresh piece of aluminum foil or petri dish.
5. Inscribe the letter “C” in the portion of the control coupons that were folded over the hanger. Assess the controls for corrosion. If they are minimally corroded, proceed. If the coupon corrosion of a given metal in one jar is significantly different from that in the other or if there is significant corrosion, repeat the experiment.
6. Using a spatula, remove the o-ring from the lid. Save and wash o-rings from “permanent” test jars. Consider sorting and saving ‘Temporary’ o-rings and coupon holders. Also consider sorting out ‘Unsuitable’ lids. It may be that with proper treatment, they can be safely reused. The Met is currently not reusing temporary or unsuitable o-rings and coupon holders, and not reusing unsuitable lids. A line is scratched on the top of lids from jars with a ‘Temporary’ result, and lids with more than 3 lines are no longer used. Lids from ‘Permanent’ jars are left unmarked and reused.
   

Lead	Copper	Silver
Figures 13 & 14: Left: acceptable amount of minimal corrosion for control. Right: too much corrosion, observed as darkening, for control.	Figures 15 & 16: Left: acceptable amount of minimal corrosion for control. Right: too much corrosion, observed as reddening, for control.	Figures 17 & 18: Left: acceptable amount of minimal corrosion for control. Right: too much corrosion, observed as yellowing, for control. Note: silver control coupons rarely show corrosion.

7. The following ratings are used to assess non-control coupons:

a. “Permanent” rating: The material tested may be used indefinitely in the presence of art.

i. Coupons look similar to the controls.

ii. Silver: remnants of polishing compounds from some manufacturers can develop or appear as white splotches. This stock is generally returned to the manufacturer, however, if it makes it into a test, the white splotches are ignored.

b. “Temporary” rating: The material is safe for use near but not in contact with art for up to six months.

i. Copper: slight reddening, yellowing, or rainbow-like color change.

ii. Silver: slight yellowing, purpling, or darkening, development of a white or orange haze on the coupon's surface.

iii. Lead: darkening, yellow/olive tarnish, haze from slight crystal formation over the entire coupon, or heavier crystal formation at the interface with the coupon holder.

c. “Unsuitable” rating: the material should not be used in contact with or near art and another material should be found.

i. Copper: severe blackening or matte-textured surface.

ii. Silver: severe color change to dark purple, yellow, or black.

iii. Lead: white fluffy crystal formation.

Photos of scored coupons from permanent, temporary, and unsuitable categories and commonly observed corrosion can be downloaded from the following links: Copper Corrosion Library, Silver Corrosion Library, and Lead Corrosion Library.

VI. Photographing Oddy Test Coupons - MMA Protocol

After being evaluated, Oddy test coupons with matching duplicate results and passing control jars are photographed using two different types of lighting: diffuse lighting using a Rosco LitePad HO90 12”x12” (figure 17), and glancing-angle lighting using a Cree XLamp CXA3050 LED with a Mean Well HLG-100H-36A power supply (figure 18). The diffuse lighting allows for proper color representation in the photograph. Glancing-angle lighting allows for the representation of surface texture in the photograph. Coupons are placed on an angled stage in between the Rosco LitePad and the white piece of paper board used to diffuse light. A photograph is taken using the diffuse lighting and another one is taken using the glancing-angle lighting. Photographs are color-corrected and processed in Lightroom.

Figure 19: image of the photo stand and its two separate light sources - glancing-angle and diffuse lighting.

Figure 20: image of the coupon stand bolted donw on the photo stand. The stage is in between the Rosco LitePad LED and the paper board used to diffuse the lighting

Figures 21 and 22: Left: image of the photo stand with only the diffuse light illuminated. Right: image of the photo stand with only the glancing-angle light illuminated.

Diffuse Light: Below are photographs of the coupon photographing stage from various angles lit with the Rosco LitePad LED.

Figure 23: image of the photo stand from behind the Rosco LitePad LED with side angle lighting.	Figure 24: image of the photo stand from in front of the camera with side angle lighting.
Figure 25: image of the photo stand from the right side of the camera with side angle lighting.	Figure 26: image of the photo stand from the left side of the camera with side angle lighting.

Glancing-Angle Light: Below are photographs of the coupon photographing stage from various angles lit with the glancing-angle LED light.

Figure 27: image of the photo stand from behind the Rosco LitePad LED with glancing-angle lighting.	Figure 28: image of the photo stand from in front of the camera with glancing-angle lighting.
Figure 29: image of the photo stand from in front of the camera with glancing-angle lighting.	Figure 30: image of the photo stand from the left of the glancing-angle light with the light on.

VII. Materials and Supplies

• Deionized H2O (18.2 MΩ) (Millipore Simplicity Water Purification System with SimPak 2 Purification Pack)
• Freeform® SE blue powder-free examination gloves (Microflex Product FFS-700-S)
• Micro-90 Concentrated Lab Cleaner Detergent (Sigma Product # Z281506-1EA)
• Shapeways laser sintered nylon coupon holder
• Water-jet stainless steel coupon holders - 'Met Oddy part' in 0.5mm 316 stainless steel
  • Order from Peter Hotkowski of Asterisk Incorporated, 50-3 River Street, Old Saybrook CT 0647; (860)388-3811, peteh@asteriskinc.com
• Kimble™ KIMAX™ GL 45 Media/Storage Bottles (Product # 02-542A) 100mL (come with caps)
• Extra caps: Kimble™ Blue Polypropylene Cap (Product # 02-542-1)
• Viton™ o-ring; size 323; Product #V75323; 75 durometer black
• Kimble™ KIMAX™ Reusable Borosilicate Glass Tubes with Plain End (Product #14-925B) 0.7mL
• Spatula & Packer Double Ended - SurgicalExcel 81-12191
• Shapeways Oddy Torque_8 Socket
• CDI 1502MRMH-QR torque wrench (2.8-16.4 Nm range)
• 3/8 in. Drive 3/4 in. 6-Point SAE Standard Socket
• Accupet 500-5000 ul Micropipette (Product #AP-5000)5 mL bulk Eppendorf-fit reference tips
• MYLAR® A 1 mil (25 micron)
• EMD Millipore 109535 MColorpHast™ pH-indicator strips (non-bleeding), pH 0-14
• 10” Stainless Steel Tongs
• Surgical Scalpel with Fitment No. 3
• Disposable No. 11 surgical blades
• Wooden handled straight point teasing needle, Part Number: 19010
• Lancer 815 LX Dishwasher
• Custom Stainless Steel Mesh Screen used to hold down lids: Material: ROUND HOLE STAINLESS PERFORATED SHEET 304 (Part#: 13523); Dimensions: 17.1” x 18.1”
• LancerClean Sodium Hydroxide (NaOH) Detergent – LCD-S
• LancerAcid Phosphoric Acid Rinse – LCA-P
  
  

Metal Preparation Material

• Micro Mesh Regular 3200
• Acetone HPLC grade
• Isopropanol HPLC grade
• Metal Coupons (99.998% Purity) - Alfa Aesar (Pb) and Fine Metals Corp. (Ag & Cu)
  • Pb : Alfa Aesar™ Lead foil, 0.1mm (0.004 in.) thick, Puratronic™, 99.998% (metals basis)
  • Ag : Silver foil, 99.998% (metals basis), annealed, 0.1 mm x 100 mm x 100 mm; Fine Metals Corporation
  • Cu : Copper foil, 99.999% (metals basis), 0.1 mm x 100 mm x 100 mm; Fine Metals Corporation
    
    

'Photographing Equipment

• Rosco LitePad HO90 (diffuse lighting LED)
• Cree XLamp CXA3050 LED (glancing-angle LED)
• Mean Well HLG-100H-36A Power Supply (for glancing-angle LED)
  

VII. Oddy Test Material Sample Preparation Guide

Material	Proposed Cutting Method
Board - composite (eg. Corian, drywall)	Cut with universal blade band saw into 0.5” cubes. Use utility knife to produce smaller pieces to make 2.0g.
Board - natural (eg. wood, cotton)	Cut with universal blade band saw into 0.5” cubes. Use utility knife to produce smaller pieces to make 2.0g.
Board - plastic/polymeric/synthetic	Cut with universal blade band saw into 0.5” cubes. Use utility knife to produce smaller pieces to make 2.0g.
Carpet - natural/non-syntheticfiber	Cut with scissors or utility knife into 1 x 1” squares. To reach 2.0 g, cut pieces that represent the sample’s composition—example: the correct ratio of carpet material, blended fibers in carpet, and base of carpet.
Carpet - plastic/polymeric/synthetic fiber	Cut with clean scissors or utility knife into 1 x 1” squares. To reach 2.0 g, cut pieces that represent the sample’s composition—example: the correct ratio of carpet material, blended fibers in carpet, and base of carpet.
Coating - floor (e.g. stain, anti-wear, anti-slip)	Follow manufacturer’s instructions regarding dilution; if to be used dry, paint out on Mylar® and cure per manufacturer’s guidelines; if to be used wet, use 0.5mL of liquid in lieu of water.
Coating - grease, oil, wax	Into a 5mL beaker, weigh 2.0 g of sample. Carefully place into the sample jar. Other borosilicate vessels that fit are acceptable as long as they are no more than 4cm tall.
Coating - paint & primer	Paint material onto a Mylar® sheet and spread to a thickness that reflects how it will be used in the museum. Cure the material according to manufacturer’s instructions. After curing, cut the painted Mylar® into 1.5” wide strips and weigh to 2.0 g, taking the weight of the Mylar® into account by subtracting it from the total sample weight. Put a small piece of Mylar® at the bottom of the jar if there’s concern about the material sticking to the glass. Roll the sample strips into a coil with the sample material facing inward, and place in the bottom of the jar.
Coating - protective (e.g. anti-UV, -abrasion, -tarnish)	Paint the material onto a Mylar® sheet and spread to a thickness that reflects how it will be used in the museum. Cure the material according to manufacturer’s instructions. After curing, cut the painted Mylar® into 1.5” wide strips and weigh to 2.0 g, taking the weight of the Mylar® into account by subtracting it from the total sample weight. Put a small piece of Mylar® at the bottom of the jar if there’s concern about the material sticking to the glass. Roll the sample strips into a coil with the sample material facing inward, and place in the bottom of the jar.
Fabric - batting & padding	Cut material with clean fabric scissors into 1 x 1” squares. To reach 2.0 g, cut small segments from a 1” square.
Fabric - book cloth	Cut material with clean fabric scissors into 1 x 1” squares. To reach 2.0 g, cut small segments from a 1” square.
Fabric - exhibition/woven	Cut material with fabric scissors into 1 x 1” squares. To reach 2.0 g, cut small segments from a 1” square.
Fiber or Thread	Cut the length of sample that weighs 2.0 g. Wind it loosely and neatly around two gloved fingers, remove, and place in the bottom of the sample jar.
Inorganic - (e.g. fillers, salts, rocks)	Keep the sample as is or prepare it as it would be used in the museum. For example, if you are testing salts, do not grind them further unless that’s how they are used in the museum setting. Weight 2.0 g of sample.
Metal - mechanical fastener	Place whole fastener in jar.
Paper-based (e.g. folder, cardboard, sheet)	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut pieces from a 1” square.
Paper-based, Filled (e.g. fillers such as silica gel, zeolites, alumina)	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut pieces from a 1” square.
Paste - filler/binder mixture (e.g. plaster, acrylic spackle, non-paint)	Extrude onto a Mylar® sheet. Spread to a thickness that reflects how it will be used in the museum setting. Cure material per manufacturer’s suggestion. After cured, peel the material from the Mylar® if possible and weigh to 2.0 g. If the material cannot be freed from the Mylar®, remove excess Mylar® and weigh the material to 2.00 g, taking the weight of the Mylar® into account by subtracting it from the total sample weight.
Polymer - adhesive - caulk or sealant	Extrude onto a Mylar® sheet. Spread a thickness that reflects how it will be used in the museum setting. Cure per manufacturer’s instructions. After curing, peel the material from the Mylar® if possible and weigh to 2.0 g. If the material cannot be freed from the Mylar®, remove excess Mylar® and weigh the material to 2.0 g, taking the weight of the Mylar® into account by subtracting it from the total sample weight.
Polymer - adhesive - glues - liquid (e.g. acrylics, wood glues, starches)	Extrude adhesives onto Mylar® sheeting in a thickness that reflects the actual material application thickness. Cure per manufacturer’s instructions. Cut the sample into 1 x 1” squares. Weigh the dried material on Mylar®, taking into account the weight of the Mylar® attached to the sample. To reach 2.0 g, cut pieces from a 1 x 1” square.
Polymer - adhesive - heat activated (e.g. hot melt, heat set)	Extrude 2” strips of melted material onto aluminum foil. Allow to cool. Peel from aluminum foil and weigh out 2.0 g of sample. If material does not remove from foil, repeat on Mylar® and account for the weight of the Mylar® in weighing the sample.
Polymer - adhesive - pressure-sensitive	Cut 2” lengths of tape, taping the adhesive sides, to the backed sides to form a small 2.0 g block of tape. Place the sample onto Mylar® to protect the jar from the adhesive
Polymer - adhesive tape - double sided	Fold the tape onto itself “accordion style” every 2” while removing the backing. Put 2.00 g sample on a piece of Mylar® to protect the jar from the adhesive, and carefully place in the bottom of the jar.
Polymer - adhesive tape - single sided	Cut 2” lengths of tape, taping the adhesive sides, to the backed sides to produce a small 2.0 g block of tape. Place the sample onto Mylar® to protect the jar from the adhesive
Polymer - block/bulk/pellet	If material comes in a block, cut into 0.5” cubes using a band-saw. If the material comes in small pellets that fit in the sample jar, use whole uncut pellets. To reach 2.0 g, shave material from one cube or pellet using a utility knife.
Polymer - foam - building insulation	For dense foam, cut with universal band saw into 0.5” cubes. To reach 2.0 g, remove material from one cube using a utility knife. For soft foams, cut material with clean scissors into a 1.5” wide strip that weighs 2.0 g. Compress the strip into a roll, and insert into the bottom of the jar. Make sure the foam does NOT touch the metal coupons when it expands.
Polymer - foam - non building insulation	For dense foam, cut with universal band saw into 0.5” cubes. To reach 2.0 g, shave any excess material on only one cube using a utility knife. For soft foams, cut material with scissors into a 1.5” wide strip that weighs 2.00 g. Compress the strip into a roll, and insert into the bottom of the jar. Make sure the foam does NOT touch the metal coupons when it expands.
Polymer - foam sealant	Cut material with clean scissors into a 1.5” wide strip that weighs 2.0 g. Compress the strip into a roll, and insert into the bottom of the jar. Make sure the foam does NOT touch the metal coupons when it expands.
Polymer - gasket	Cut material with clean scissors into 2” length strips.
Polymer - glove	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut pieces from a 1” square.
Polymer - membrane (<1mm thick)	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut pieces from a 1” square.
Polymer - sheet (>1mm thick)	Cut material with clean scissors into 1 x 1” squares. To reach 2.0 g, cut a minimal amount of strips from a 1” square.

Missouri Historical Society (MHS) Oddy Test Protocol

The method MHS uses is primarily taken from the published protocols of the Metropolitan Museum of Art (Version 20190226_OT_1 published on the AIC Oddy Test wiki site). Some steps have been altered, following the British Museum’s “Refinements Introduced in the Oddy Test Methodology” (Studies in Conservation, Volume 63, 2018 – Issue 1).

I. Personal Protection Equipment (PPE): Nitrile gloves, safety glasses, and a laboratory coat are worn throughout this procedure. Wash hands with soap and water prior to donning gloves to remove oils. Care is taken to always handle the metal coupons with tweezers while wearing clean nitrile gloves. Handling coupons with dirty or oily hands/gloves can cause coupon contamination.

II. All testing components must be handwashed before being used.

Note: New components are always washed before using. See Appendix 1 for list of supplies.

**Lids, nylon coupon holders, and O-rings from failed test jars are NOT reused.** **Nylon coupon holders and O-rings from temporary test jars are NOT reused.**

Lids, nylon holders and O-rings from permanent test jars can be reused. Lids from temporary test jars can be reused – but they must be tracked and when a lid has been in a temporary test 4 times, it is no longer reused.

These practices were established to avoid the possibility of contamination from one test to another.

Handwashing Method

Glass Jars and Tubes

1. Create a solution of 2% (v/v) Decon 90 in tap water.
2. Soak jars and tubes in the solution for 2 hours and then scrub clean with a clean brush to remove any residues or particulate matter left in the tubes.
3. Each component is then subjected to three agitated rinses in tap water and a final rinse in deionized water before being left to dry in an oven set to 60° C

Lids, Nylon Coupon Holders and O-rings

1. Wash lids, nylon holders and O-rings in the 2% (v/v) Decon 90 solution by dipping them in the cleaning solution and rubbing with gloved hands or a clean sponge. Do NOT soak for any length of time in the Decon 90 solution.
2. Rinse 3 times in warm tap water and a final rinse in deionized water before being left to dry in an oven set to 60° C.

III. Metal Coupon Preparation: Use only high purity metals (99.998% or higher).

*All metals are stored immediately upon receipt from the supplier within an Intercept® zip-top bag.*

**Use a dedicated pair of scissors for each metal.**

**Use a separate piece of sandpaper for each metal**

1. Measure and cut silver (Ag) and copper (Cu) into coupons measuring 0.8 cm x 2.5 cm.

   a. If the silver or copper metals have signs of oxidation, then they should be polished first with 3200 grit Micromesh sandpaper to remove any signs of corrosion. (Cutting large strips of metal before sanding and then cutting them down into coupons after sanding makes the sanding process quicker and more efficient.)]]

2. Soak the silver and copper coupons in a small beaker of acetone (HPLC grade) and wipe dry with a Kimwipe®.
3. Next, soak the silver and copper coupons in a small beaker of isopropanol (HPLC grade).
4. Cut lead (Pb) into strips that are 10 cm long by 0.8(x) wide, with “x” being the number of skinny strips you want. Each skinny strip yields 4 coupons. Cutting large strips of lead before sanding and then cutting them down after sanding makes the sanding process quicker and more efficient.
5. Place a 12 inch by 12 inch flat glass plate inside the filtration box, and place the un-sanded 10 cm x 0.8 cm lead strips on top of the glass plate. The strips should be made as flat as possible before sanding (any folds or creases will make it more difficult to achieve an even texture after sanding).
6. Cut a 2 inch square piece of 3200 grit Micromesh™ sandpaper into 2 inch squares and fold it in half twice to form a 1 inch square with grit on both sides.
7. To sand, use a gloved finger to hold one end of the lead strip. While sanding, hold the Micromesh™ under one thumb so that the pad of the thumb is flat when applying pressure and covers the entire width of the lead strip.

   a. Sand from the center of the strip to the end away from the user, using even light pressure (video demo available at https://www.youtube.com/watch?v=z7aNXdArQqs)

   b. Avoid using the tip of the thumb or pressing part of the thumbnail into the Micromesh™.

   c. Change the position of the Micromesh™ every 15 – 20 strokes to an unused portion of the Micromesh™.

   d. Every stroke should be straight and run all the way from the middle of the strip to the far end.

   e. Approximately 45 strokes will properly sand a single section of lead. Once the first section is sanded, rotate the strip 180°and sand the second half of the same side. Then flip the strip over and sand the other side using the same technique.

   f. If the lead strip elongates or stretches longer than 10 cm, then too much pressure is being applied. The goal is to remove the native oxide, leaving a surface with uniform roughness, applying minimal pressure. A correctly sanded lead coupon is lighter in shade than the un-sanded lead and has a consistent overall texture with no shiny patches of specular reflection.

8. After sanding the 10 cm long lead strips, rinse each side with a Kimwipe® dipped in acetone. Repeat until the Kimwipe® wipes clean. Next dip a Kimwipe® in isopropanol and wipe each side of the lead strip. Repeat. (video demo: https://www.youtube.com/watch?v=4_XlEE9-vwA )
9. Cut the large lead strip into skinny 0.8 cm x 10 cm strips. Cut each 0.8 cm lead strip into four 0.8 cm x 2.5 cm coupons.
10. Remove silver and copper coupons from isopropanol beaker and wipe dry with a Kimwipe®.
11. Collect rinse solutions and dispose of as hazardous waste.
12. Dispose of Kimwipe®, Pb-contaminated gloves, and sandpaper as lead-contaminated hazardous waste.

IV. Jar preparation and assembly
Run all tests in duplicate, including controls. Produce one set of controls for each group of tests.

1. Place a sheet of weighing paper on the scale and tare to zero.
2. Weigh 2g of test sample material on the paper and load into a 100 mL borosilicate jar.

   a. See Appendix 2 for a sample preparation guide.

3. Dose 0.5 mL 18.2 MΩ-deionized water into a borosilicate mini-test tube using a recently calibrated micropipette.
4. Place the mini-test tube with water into the jar (using a clean pair of tweezers to lower it in is helpful).

   a. The tube is slightly longer than the diameter of the jar, so the tube will be propped up at an angle against the side of the jar.

5. To a pre-washed 3D printed nylon coupon holder, attach the metal coupons by bending the coupon 5-7mm from one end and crimping it onto the holder. Insert the coupon holder into the mouth of the jar.

   a. Make sure the coupons do not come into contact with each other, the jar, or test material.

   b. For the in-contact variant, using tweezers, on each coupon fold over one corner 1-2mm. Make sure the test material in the jar lays as flat as possible and place a Cu, Ag, and Pb coupon on top of the material so that the folded triangle flap of each coupon face up toward the mouth of the jar and the smooth side of the coupon is facing down toward the bottom of the jar.

   i. Smooth side should be fully in contact with the sample material and none of the coupons should be touching each other or the glass sides of the jar.

   ii. In control jars, place the coupons on the bottom of the jar in the same orientation as sample jars.

6. Insert a pre-washed Viton o-ring into each lid and lightly screw the lids onto the jars.

   a. If a custom socket is available from the Met, then tighten the lids to a torque of 4 Nm using a torque wrench fitted with the custom socket.

   b. IF a custom socket is not available, tighten the lids by hand as much as possible.

7. Weigh each jar and record the values.
8. Place jars in oven leaving as much space between jars as possible for air circulation, with the jars standing upright.
9. Leave the jars in oven at 60°C for 60 minutes.
10. Remove jars and re-tighten lids while warm by hand (or with a wrench to a torque of 4 Nm if custom socket is available.
11. Return jars to oven and age at 60° ± 1.5°C for 28 days.

V. Assessment at completion of testing

1. After 28 days in the oven, remove jars from oven, and allow to cool to room temperature.
2. Record weights of each jar.

   a. Compare to pre-aged weights to determine whether each vessel was sealed during the experiment.

   b. A loss greater than 25% of the water mass (25% of 0.5 grams, or a loss of more than 0.13 grams) is considered a system failure, and the experiment is repeated.

3. Open jars and lift the coupon holders out of the jars. Remove coupons from the coupon holders using tweezers.
4. Unfold the coupon where it was crimped over the coupon holder. Scribe the inside of each coupon across the width of the coupon where it met with the holder using a dissection needle.
5. Press the coupons flat using two blocks of polished flat stainless steel, aluminum, or glass. Place the coupons on a fresh piece of aluminum foil or petri dish.
6. Inscribe the letter “C” in the portion of the control coupons that were folded over to avoid mixing samples during coupon evaluation.

   a. Assess the controls for corrosion. If they are minimally corroded, proceed.

   b. If the coupon corrosion of a given metal in one jar is significantly different from that in the other OR if there is significant corrosion, repeat the experiment.

7. The following ratings are used to assess non-control coupons:

   a. “Permanent” rating: The material tested may be used indefinitely in the presence of artifacts.

   i. Coupons look similar to the controls.

   ii. For silver, remnants of polishing compounds from some manufacturers can develop or appear as white splotches. This stock is generally returned to the manufacturer, however, if it makes it into a test, the white splotches are ignored.

   b. "Temporary” rating: The material is safe for use near but not in contact with artifacts for up to six months.

   i. Copper: Slight reddening, yellowing, or rainbow-like color change, formation of up to 20 black spots.

   ii. Silver: Slight yellowing, purpling, or darkening, development of a white/orange film.

   iii. Lead: Darkening, yellow/olive tarnish, haze from slight crystal formation over the entire coupon, or heavier crystal formation at the interface with the coupon holder.

8. Using a spatula, remove the o-ring from the lid. Save and wash o-rings from tests that pass with a “Permanent” rating. Toss out those that receive a “Temporary” or “Unsuitable” rating.
9. Save and wash coupon holders from tests that pass with a “Permanent” rating. Toss out those that receive a “Temporary” or “Unsuitable” rating.
10. Save and wash lids from tests that pass with a “Permanent” or “Temporary” rating. Toss out those that receive an “Unsuitable” rating.

    a. Scratch a line in the top of lids that receive a “Temporary” rating. Lids with more than 3 lines will be tossed.

    b. Lids from “Permanent” jars are left unmarked and reused.

    c. Always use at least one new or unmarked lid per pair of materials jars tested.

11. Photograph coupons under diffuse light and raking light and save images.

VI. Photographing Oddy Test Coupons

1. Photograph coupons under two different types of lighting: direct and raking.
2. Devices set up.

   a. Set up the Lastolite 5-sided light tent cube

   b. Camera: Using ‘[pro]master Boom Light Stand LS-6’ tripod, shoot straight down from the above the light tent cube

   c. Stand lights: 45 degree from the above both side (Direct); one right side (Raking)

3. Coupons set up.

   a. Set up control coupons and sample coupons on the designated place on the blue board

   b. Put Calibrite Colorchecker aside of the coupons

   c. Put label of Oddy test # and date below the coupons

4. Save the images.

   a. File naming protocols: Oddy Test #_Date (8 digit – YearMonthDay)_Direct or Raking.gif

   b. Save images for uploading to the AIC Wiki

   i. Resize to 900 pixel width

   • Choose image > Resize > Image Size
   • Select “Resample Image” > Drop down box select “Nearest Neighbor”
   • Select “Constrain Proportions” to maintain current ratio
   • Enter pixel width to “900” > Select “OK” to save pixel of image

   ii. Save images as jpeg

Selected Bibliography:

Bamberger, J., E. Howe, and G. Wheeler. 1999. A variant Oddy test procedure for evaluating material used in storage and display cases, Studies in Conservation. 44:86-90.

Blackshaw, S. M. and V. D. Daniels. 1979. The testing of materials for use in storage and display in museums. The Conservator 3:16-19.

Green, L. R., D. Thickett. 1993. Interlaboratory comparison of the Oddy test. Conservation science in the UK: preprints of the meeting held in Glasgow, May 1993. ed. N. H. Tennent. London: James & James Science Publishers Ltd. 111-116.

Green, L. R., D. Thickett. 1995. Testing materials for use in the storage and display of antiquities - a revised methodology. Studies in Conservation 40:145-152.

Lee, S., H. Roh,Y. Yi. 2004. Effects of wood materials on metal corrosion – Oddy test. Conservation Science in Museum 5:31-36.

Oddy, W. A. 1973. An unsuspected danger in display. Museum Journal 73:27-28.

Zhang, J., D. Thickett, L. Green. 1994. Two tests for the detection of volatile organic acids and formaldehyde. Journal of the American Institute for Conservation 33:47.53.

National Archives of Australia (NAA) PAT Protocol

The NAA carries out the Photographic Activity Test (PAT) according to the ISO 18916:2007 Imaging materials – Processed imaging materials – Photographic activity test for enclosure materials. The test is described on their site along with results of materials that have passed since 1996. The complete protocol is described in greater detail on the IPI site.

National Museum of the American Indian (NMAI) Protocol

Current Protocol:

Dates: 2019 - current
All tests follow the 2020 IMA/Winterthur protocol outlined on this page. Tests are carried out in duplicate.

Protocol 2011-2019:
I. General Overview/Test Type
The test is performed by placing the material being tested in a sealed glass vial with metal coupons (silver, copper and lead) and water at 60°C for 28 days. A blank/control of water and coupons without other materials is also tested. Possible hazards to collections items are indicated by the severity of corrosion on the metal coupons. At the NMAI the test has been modified over the years and uses both ‘non-contact’ method, when the material is not in contact with the metal coupons and the ‘contact’ method, when the material is in direct contact with coupons. The contact method is done to capture the changes to the metal coupons caused by surface finishes often applied to contemporary materials, for example, stain repellent finish on inert polyester fabric.

II. Washing Methods for Glassware
1.      Wash glass tubes in water with laboratory detergent, using brush.
2.      Rinse with acetone.
3.      Place in the fume cupboard to dry.
4.      Mark the tubes with glass pencil as per the Oddy Test Record Sheet.

III. Sample Preparation
1.       Fabrics and other sheet materials should be cut into small pieces for maximum surface area. Construction materials such as wood and solid plastics should be cut into 1.5 cm cubes that fit into the glass tube with enough space to also insert vial with water

IV. Metal Coupon Preparation
1.      Clean scalpel, tweezers and scissors with acetone before use.
2.      Abrade the foil surface on both sides with a glass bristle brush to remove any oxide layer from the metal surface. Do this on paper or tyvek that can be disposed of afterwards, not directly on the table. Caution: protect yourself from glass fibers from the brush and from heavy metal dust, especially lead. Wear personal protective equipment when cleaning coupons and dispose of cleaning material (swabs, paper towels, etc.) as hazardous waste according to established protocol.
3.      Cut metal coupons to size, approx 10 mm x 40 mm. Clean the coupons in acetone by placing them in 3 separate dishes (copper, silver and lead) filled with acetone and cover the dish with glass lid. Hold the coupons with tweezers and dry them with a tissue (Kimwipe); do not leave the coupon to dry off by itself. Store the coupons in 3 separate dishes, covered with glass lid.
4.      Wipe the boards used to cut and polish metal coupons with acetone to remove metal dust. Vacuum clean area thoroughly to remove any glass fibers.

V. Jar Preparation and Assembly
Non-contact method
1.      Place minimum 2 g (or more if necessary) of the material at the bottom of each tube. Also place the small glass tube filled with 0.5 ml of distilled water at the bottom of the tube, closed with a small piece of cotton wool. Always set 2 non-contact tubes for the same material.
2.      Put 3 slots in the bottom of the silicon stopper with the scalpel. Insert a metal coupon in each slot, ensure the coupons do not touch each other or the glass of the tube.

Contact method
1.      Place the small glass vial filled with 0.5 ml of distilled water and topped with a small piece of cotton wool at the bottom of the tube.
2.      Place the material on the bottom of the tube and arrange metal coupons on the material in such a way that they a) do not touch each other and b) that one half of the coupon is in contact with the material and the other is not, either suspended or rests on the bottom of the tube (Fig. 2, this is especially important if you are only using ‘contact’ method as it will help assess changes to metal by off-gassing and by direct contact with the material).  Always prepare 2 contact sets (i.e. two test tubes) for the same material.

Closing the tube
Ensure that the coupons for the contact method keep their location on the material and the water tube is upright with no water spilled on the material or coupons. Without disturbing the contents, close the tube with the stopper & make sure the tube is well sealed by pushing the stopper in. To seal the stopper, wrap Teflon tape around the seal line and around the bottom and over the top of the test tube to prevent loss of moisture and volatiles.

Control tubes
1.      Control tubes are made in the same way but without the test material.
2.      Replicate the test run: If doing contact and non contact, prepare two controls with coupons in the stopper and two controls with coupons on the bottom of the test tube.
3.      Always prepare 2 control tubes for the whole batch of materials tested.

Oven
1.      Place the tubes into a large diameter low beaker, this helps to stabilize the tubes and keep them upright when moving into the oven. Place the beaker in the oven at 60°C for 21 days (Though literature says 28 days, our in-house tests have found that there is not much additional change between 21 and 28 days)

VI. Coupon Assessment
1.  After 21 days the metal coupons are removed from the tubes using tweezers and compared with the control coupons.
2.      Carefully note the position of the contact coupons: both which side and which part was in contact with the material. When taking the coupons out for the ‘contact’ tubes, ensure they are placed on a piece of paper reflecting the way they were positioned in the tube. You can develop your own system for keeping track but be consistent. For example, place the coupons with the contact side up and facing to the left, so that the ‘contact’ and ‘non-contact’ sides of the coupon are not confused. Arrange all the coupons on a sheet of paper and write down the corresponding tube number of the test.
·      The Oddy test results are subjective because the coupons are examined visually and evaluated based on comparison and experience.  Ask conservation staff member to help evaluate the results.
·      The level of corrosion is used to place the material into 3 categories: Pass (for permanent use), Pass/T (for temporary use) & Fail (fail completely).
Pass: suitable for use. No changes to the coupons compared with controls. Some minor red/orange iridescence often appears on the copper. Coupons should not have lost polished surface. Lead control will have a duller hue.
Pass/T: suitable for temporary use, up to six months. There is a slight discoloration, sometimes along the edges, & slight corrosion to the coupons.
Fail: unsuitable for use.  Clearly visible corrosion, loss of polish that indicates a thin corrosion layer over the surface

VIII. Materials and Supplies
1.      150 ml glass tubes - at the NMAI tests are set in duplicate as a measure of reproducibility. This means if you are running ‘contact’ only test, you will need 2 tubes, and if both, ‘contact’ and ‘non-contact’ test, you will need 4 tubes for each material tested, and corresponding number of metal coupons and test material samples. Two control tubes are always tested alongside the sample for each type of test.
2.      2 g of the test material for each tube as a minimum
3.      Silicone stoppers
4.      Small glass vials (0.8 ml)
5.      Metal foil (Ag, Cu, Pb)
6.      Cotton wool
7.      Distilled water
8.      Acetone
9.      Three dishes (one for each metal)
10.  Pipette
11.  Scalpel
12.  Tweezers
13.  Scissors
14.  Tissue.

References 
L.R. Green & D. Thickett. 1995. Testing Materials for Use in the Storage and Display of Antiquities: A Revised Methodology, Studies in Conservation, 40 (3), 145-152.
L. Robinet & D. Thickett. 2003. A New Methodology for Accelerated Corrosion Testing, Studies in Conservation, 48 (4), 263-268.

Protocol 2003-2011:
I. General Overview/Test Type

• Run at least two samples of each material, ideally three.  Always run one control containing no test sample, per batch.
• The time the test will take depends on the temperature it is run and what is involved in sample preparation. Our tests are run at 60C for three weeks, which is an accelerated version of SCMRE’s method of 4 weeks at 50C. When estimating the time it will take, allow for time for sample preparation. Coatings will need additional time to off-gas.
• The metals you choose to use may change depending on what you are testing for. Lead, being more sensitive, may act as a sacrificial metal (this point was brought up after the AIC paper, 2003).  If a material corrodes the lead but not the copper and the silver, the material should be tested separately with the copper and silver before deeming it safe for either.
• If possible, run the test material with a currently accepted standard. This will help decide if the benefits of replacing the accepted standard (which may be related to economics rather than chemistry) outweigh the disadvantages.
• Get as much information about the sample as possible: technical data, MSDS sheets, and if possible, the age of the sample and date of manufacture.  Also find out its intended use; a more specific test may prove more useful.

II. Washing Methods for Glassware
1.      All glassware is cleaned with Sparkleen™ detergent, rinsed with deionized water, then acetone, and allowed to air-dry in the fume hood or oven.
2.       Chemglas™ coupon holders are wiped with acetone and a kimwipe™ and allowed to air dry.

III. Sample Preparation
1.      Graphite pencil can be used to label the beaker your sample is in.
2.      Keep cutting instruments clean to avoid cross-contamination.
3.      Films such as paint or adhesive can be painted out on Mylar™ and then put in the beaker.  

Considerations:

• Some materials, like silver cloth, may absorb contaminants.  It is good to keep samples sealed in polyethylene bags.
• It is generally recommended that 2g of sample be used, but sometimes, especially with textiles, 2 grams will not fit in the test vessel.  When deciding whether to use weight or volume, to standardize the amount of sample you use, consider how the material will be used.  For instance, paint or fabric will be measured using surface area, no matter what the weight is – it makes sense then to use a specific surface area then a specific weight in the test vessel.
• The time that paints and wood products are allowed to off-gas will affect the amount of volatiles they give off. This also applies to cut edges of wood products – try to prepare them all at the same time.
• It may be helpful to have test coupons both in contact and not in contact with the tested materials. To do a contact test may require some creativity in getting part of the material to contact the coupons. Consider things such as end-grain, top grain, and how these might affect the test differently – keep your test consistent.
• Cutting up your sample increases its surface area, and the amount of volatiles it can give off.  Whether you decide to do this or not depends on how you stringent you want your test to be.  When comparing two materials, ensure they are in the same form, and the same amount for consistency.

IV.Metal Coupon Preparation
For our purposes of photographing the coupons, we cut them each 20 mm by 5 mm so that all three would fit into the picture frame.  First, we marked a strip 15 mm wide on the metal using a dull knife blade and a ruler, then cut the strip with scissors.  It was helpful to have the standard sizes marked on a piece of cardboard, so that all of the coupons are similar in size.

Remember to:

• Wear gloves to avoid getting oil and dirt from hands on the metal surface (The Conservation Dist - thread 07/10/2003 – posted concern about contact from nitrile corroding metals. Vulcanizing agents in the nitrile can contribute to corrosion.  Polymer coated gloves may provide protection. To prevent nitrile gloves from contaminating the coupons, after they are cleaned we use only stainless steel tweezers.
  
• Rinse scissors and knife blades in acetone before using.
  
• Work on an absorbent surface such as acid free cardboard, or Kimwipes ™.
  
• Use separate work surfaces for each metal to prevent cross-contamination resulting in galvanic corrosion.  For each metal, a glass bristle brush for cleaning, and a piece of acid-free cardboard is kept in a separate polyethylene bag.
  

Use a glass bristle brush to clean both sides of the metal strip (some conservators felt that the scratchy surface on the metal would mask any etching effects from the material when running a contact test.  Further discussion with Walter Hopwood said that etching that may occur could be a result of an acidic reaction between carbon dioxide and moisture trapped between the material and the metal, and not the material itself, and so the scratchy surface is not masking a reaction between the material and the metal.  Carbon dioxide varies from vessel to vessel, which may result in a difference in dullness between lead coupons).  After the metal is clean, handle metal coupons with stainless steel tweezers only. Use a piece of Groomstick™ to pick up loose glass bristles off the cardboard surface – watch your fingers!
The metal strip is cut into coupons. Mark the width of the coupon with a knife blade and ruler and cut with scissors.  Repeat the procedure for each metal used in your test.

• Change work surfaces so that dust from one does not contaminate the other metals.  Because this can be dusty, you may want to do this in the fume hood.
  

After the coupons are polished and cut, they are degreased using acetone and wiped dry with a Kim-wipe ™. To save on paper, one Kim-wipe™ (in each plastic container) is designated to dry each type of metal.

• Do not let the coupons air-dry – as the acetone will leave a mark on them (Robinet, Personal Communication, 2003).
  

1.      The coupons are then inserted into a ChemFab™ holder.  The holder was designed to lessen direct handling of the coupons, and to help with photography, which is very effective in communicating test results to other museum personnel.
2.      The ChemFab™ holder has two horizontal slits over which both ends of the coupon are wrapped. This helps to keep the coupons vertical in the jar so that water is less likely to fall on their surface.
3.      It helps to squeeze the holders to open the slits when inserting the coupons.
4.      To avoid galvanic corrosion, make sure there is space between the coupons in the holder.

V. Jar Preparation and Assembly
Now the “Oddy test chamber” can be assembled

• Try to keep the card vertical in the beaker.  The bottom end of the card can be bent so that it stands straight.
  
• For contact tests, the card can be trimmed and placed directly on the sample, slightly askew so that part of each coupon contacts the sample directly, and part is exposed to the air inside the chamber.
  

2 ml of deionized water is added to the shell vial inside each chamber, for a water to free space ratio of 1:70.

• It is faster to mark 2mls on a syringe and fill each shell vial accordingly.
  

Once the lid is on, your Oddy test is ready to go into the oven.

• After they have been in the oven for about ½ an hour, tighten the lids of the jars.

Disposal
After test coupons are documented, they should be sealed in a plastic container and labeled as Ag, Cu, Pb. Swabs and Kimwipes™ can be accumulated in a zip-lock bag. Both should be stored in the fume hood in a hazardous waste container, and the start dates and contents labeled.

VI. Coupon Assessment
Interpreting results
The Oddy test can be used to inform the decision to use a material but should be combined with knowledge of the material’s chemical components and its ultimate use.  Some museums classify their test materials as good for permanent exhibits, temporary exhibits, or unsuitable for use. Another approach is to describes the results qualitatively and rank their materials within each batch according to amount of corrosion.

Considerations

• If the water has dried out from the test vessel, expect to see less corrosion on the coupons than if the water remained in the test vessel.  Re-test the material before passing.
• If water has condensed on the coupons, there may be corrosion on the coupon that would not be there otherwise. Re-test the material before failing.
• Some oxidation is likely to occur on the metals during the test, even without a suspect material present.  Slight dulling of the lead could be due to variable levels of carbon dioxide in the jars (Hopwood, Personal Communication, 2003). Ignore this as well as any slight color variation. Likewise, an orange or red iridescence on the copper is ignored (Robinet, Personal Communication, 2003). The silver should remain unchanged.
• When comparing the extent of the corrosion, compare only with materials that have been tested at the same time, as the test conditions may vary between batches.
• The lead may act as a sacrificial metal. If the lead corrodes, but not the copper or the silver, the sample should be tested separately with the copper and silver before declaring it safe for these metals.

VIII. Materials and Supplies

Material	Ordering Information	Notes
Copper foil, 0.005” thick	S75096 Fisher Science Education http://www.fishersci.com	Manufacturer confirmed these were >99.5% pure.
Silver foil, 0.005” thick	S80162 Fisher Science Education http://www.fishersci.com	Manufacturer confirmed these were >99.5% pure
Lead foil, 0.004” thick	42708 Alfa Aesar http://www.alfa.com Phone: (800) 343-0660 26 Parkridge Road Ward Hill, MA 01835-6904	Manufacturer confirmed these were >99.5% pure
125 ml I-chem jars	Catalog number: 05-719-57 I-Chem No.:320-0125 Fisher Scientific Phone: (800) 766-7000 Fax: (800) 926-1166 http://www.fishersci.com	We got the pre-cleaned ones to save a cleaning.  However, after use some of them began to delaminate – a boroscilicate equivalent would be better.
Dow Corning High-Vacuum Grease	Grease 14-635-5D     5.3 oz     Fisher Scientific Phone: (800) 766-7000 Fax: (800) 926-1166 http://www.fishersci.com
10 mil Premium Chemglas™ fabric for coupon holders	Saint-Gobain Performance Plastics 150 Gaylord Street Elk Grove Village, Illinois 60007 1-800-323-6677
GroomStick™ (unvulcanized natural latex rubber.	Made by Picreator Enterprises Ltd.  Available from University Products, 157 Main Street P.O. Box 101, Holyoke, MA 01041-0101. 1-800-628-1912 and Gaylord, P.O. Box 4901, Syracuse, NY 13221-4901. 1-800-448-6160.
Fine glass brushes	From Conservation Support systems (1-800-482-6299): 3 fine Rope scratch brushes Cat.No. description: 1-56-12 BR-73000
Other materials needed:
Corrosion Intercept bags (for storing copper and silver) and Static Intercept bags (for storing lead)	Engineered Materials, Inc. 113 McHenry Road, #179, Buffalo Grove, IL 60089 Phone (847) 821-8280 Fax (847) 821-8260 www.staticintercept .com
20 ml beakers	Pyrex 20 mL Beakers 02-540E Fisher Scientific Phone: (800) 766-7000 Fax: (800) 926-1166 http://www.fishersci.com
Shell vials, boroscilicate glass 45mm x 15mm	Fisherbrand Glass Shell Vials 03-339-26B. Phone: (800) 766-7000 Fax: (800) 926-1166 http://www.fishersci.com
KimWipes™ Low-lint, single ply, non-abrasive tissue wipers.	(Kimberly-Clark).  Available from Thomas Scientific, P.O. Box 99, Swedesboro, NJ 08085. 1-800-345-2100.
Gloves
Scissors
Knife
Acid free cardboard
acetone
Additional Materials Testing Equipment
AD strips	Image Permanence Institute Rochester Institute of Technology 70 Lomb Memorial Drive, Rochester, NY 14623-5604 Phone: 585-475-5199  Fax: 585-475-7230
pH strips	ColorpHast indicator Strips pH 0-14 EM Science 480 Democrat Road Gibbstown, N.J. 08027

New York University Libraries (NYUL) Oddy Test Protocol

Oddy test procedure:

All tests follow the Metropolitan Museum of Art 20190226_OT protocol outlined on this page above, except glassware is washed by hand using Alconox cleaner only.

Penn Museum (Penn) Protocol

Oddy test procedure:

All tests follow the Autry Museum protocol outlined on this page above. Tests are carried out in triplicate.

Silver Nanofilm Sensor Protocol to test housing materials for Daguerreotypes by Robyn Hodgkins et. al.

The following protocol is outlined in the following article "Silver Nanofilm Sensors for Assessing Daguerreotype Housing Materials in an Oddy Test Setup" published by Robyn E. Hodgkins, Silvia A. Centeno, Joseph A. Bamberger, Masahiko Tsukada, Alejandro Schrott in e-Preservation Science, 2013. In this work, an Oddy test enhanced with silver nanofilms was utilized for evaluating a variety of materials typically employed for housing sensitive silver images, including daguerreotypes. The silver nanofilm sensitivity was compared to silver foil used in the standard Oddy test and to daguerreotype image samples. The resulting procedure allowed for facile visual evaluation of the silver films after exposure and reduced the length of the test.

Experimental Materials:
The Oddy test materials include:

• silver foil (Aldrich, 0.025 mm, 99.9%),
• copper foil (Aldrich, 0.127 mm, 99+%),
• lead foil (Alfa Aesar, 0.1 mm, 99.9%),
• 20 mL Pyrex beaker (Corning Incorporated),
• 125 mL I-Chem clear short wide mouthed jar and lid (Fisher Scientific),
• Dow Corning high vacuum grease, and
• deionized water.

Silver film materials include:

• silver shots (Aldrich, 1-3 mm, 99.99%) and
• petrographic slides (Buehler, 27 x 46 mm).

Slide cleaning supplies include:

• Alconox (anionic powder detergent, Alconox, Inc),
• ethanol (HPLC grade, Fisher Scientific),
• acetone (HPLC grade, Fisher Scientific),
• hydrochloric acid (ACS Plus, Fisher Scientific),
• crystallizing dish (170 mm, Pyrex),
• shaker (Thermolyne Rotomix Type 48200), and
• Dust Off dis- posable compressed gas duster.

The gilded daguerreotype samples used in this study, made by contemporary artist Jerry Spagnoli, were examined by SEM-EDS before testing and were found to have image particles within the typical range of diameters and compositions of those observed in 19 th century plates.

Procedure

Before silver film formation, glass slides were cleaned in a crystallizing dish to remove surface contaminants as follows: 1) washed for 15-30 min in an aqueous solution of Alconox; 2) rinsed briefly in deionized water to remove residual Alconox; 3) washed in 1% v/v HCl for 15-30 min to remove any residues; 4) rinsed in deionized water and washed for 15-30 min in water to remove HCl; 5) rinsed briefly in ethanol then washed in ethanol for 15-30 min to dehydrate; and 6) rinsed and washed with acetone for 15-30 min to finish cleaning. After cleaning, slides were submerged and stored in acetone at room temperature until use. Slides were dried immediately before use with a compressed gas duster. Silver nanofilms were made using an Edwards Vacuum Coating unit E306A comprised of an E2M8 rotary vacuum pump, E04 vapor diffusion pump, Pirani 10 vacuum gauge, Penning 8 vacuum gauge, FTM6 quartz crystal microbalance film thickness monitor, and a variable transformer. The films were formed under a vacuum of 2 x10 -6 mbar at a deposition rate of 0.025 nm/s to a desired thickness of 7- 200 nm. The films were stored in a sealed bag with silica gel condi- tioned at 33% RH to prevent tarnishing when not immediately used.

Testing
The MMA 3-in-1 Oddy test configuration is described in detail by Bamberger et al. 8 For this method, deion- ized water (2 mL) is added to the I-Chem jar first. The metal foils are folded over the edges of the 20 mL beaker and the material to be tested (typically 2” x 1”) is placed inside the 20 mL beaker which is then secured with grease to the bottom of the I-Chem jar. The threads of the jar are coated with grease and the jar is sealed. The test setup is placed in the oven at 60 °C for 4 weeks. After the first 5 min in the oven, the lid is tightened another eighth to a quarter turn. A subset of materials was also tested using 1 mL of deionized water for comparison.

Oddy test using daguerreotype image sample, silver foil, and wool The standard Oddy test assembly was used for daguerreotype image sample tests. Only silver foil was used and the daguerreotype image sample was placed at the bottom of the beaker with the wool sample but not in contact. Tests were conducted for 1, 2, and 4 weeks at 60 °C.

Oddy test using silver nanofilms The Oddy test involving the silver nanofilms used the same glassware assembly as the 3-in-1 Oddy test. The material of interest was placed at the bottom of the 20 mL beaker and the silver nanofilm slide was placed on top of the sample (Fig. 1). The test setup was placed in the oven at 60 °C for 1 or 2 weeks.

Evaluation:

Rating of materials For the standard Oddy test, corrosion results were ranked on the scale from 1 to 5; 1 being no obvious change and 5 being obvious change in color with majority of the surface corroded. The ranking for all three metals are compared and a final overall rating is given for the material: pass (P), temporary (T), or unsuitable (U). 7,8 If a 4 or 5 ranking is given for one metal, the material is considered unsuitable. For the Oddy test with silver nanofilm, corrosion results are pass with no obvious discoloration, or unsuitable with brown discoloration that can be a few spots or the entire film. Daguerreotype image samples, nanofilms, and foils were photographed before and after each test using a Canon EOS 5D Mark II camera and Interfit Digilight 600 lights with Canon EOS Utility and Adobe Lightroom 3 software programs.

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